Category: Emergency Procedures

Ultrasound-Guided Vascular Access (2025)

~ iEM Education Project Team ~ Leave a comment

by Zackary Funk & Petra Duran-Gehring

Authors
Listen

Introduction

Ultrasound (US) guidance has become an increasingly common technique for vascular access in the Emergency Department (ED), with applications for both central and peripheral lines [1-4]. Initially adopted for central venous catheter (CVC) insertion, particularly in the internal jugular vein, US improved placement success rates, decreased complication rates, and shortened insertion times. As US technology and training advanced, its use expanded to peripheral intravenous line (PIV) placement, where studies have demonstrated increased success rates, reduced complications, and less pain, especially for patients with difficult access [1-4]. Difficult IV access, occurring in 10% to 30% of ED patients—particularly those with morbid obesity, IV drug use, hypovolemia, or chronic illness—can delay cannulation due to multiple failed attempts [5]. Ultrasound-guided PIV placement can mitigate these challenges, with one study reporting an 85% reduction in the need for CVCs in non-critical patients through the implementation of a US-guided PIV catheter program [6]. The overall benefits of US-guided vascular access include improved success rates, fewer complications, decreased pain, reduced time to cannulation, fewer attempts required, and improved patient satisfaction [1-4]. While it may add some complexity compared to landmark or “blind” approaches, the ability to directly visualize target vessels makes US-guided vascular access a highly effective and patient-centered technique.

Indications

Intravenous (IV) access is often critically important for many aspects of patient care in the ED [1-3]. These include:

US-Guided Peripheral IV Access:

  1. Patients who have had three or more blind attempts without successful cannulation.
  2. Patients with a history of difficult IV access.
    • Always evaluate the patient using traditional visual inspection and palpation before preparing for US-guided peripheral IV access. Factors that contributed to difficult IV access during previous encounters, such as hypovolemia, may not be present during subsequent visits.
  3. Patients who have previously required central line placement solely for IV access.
    • As mentioned above, when the clinical situation permits, patients with a history of requiring US-guided vascular access should be evaluated for landmark-based IV sites and/or US-guided peripheral IV sites before proceeding to the more invasive procedure of central venous access.

US-Guided Central Venous Access:
Whenever possible, it is highly recommended to use ultrasound guidance for invasive vascular access procedures, such as central venous cannulation, due to its demonstrated ability to decrease the occurrence of severe complications and increase success rates. The primary indication for ultrasound guidance in central venous access is the need for central venous access itself. Below is a list of specific indications for central venous access [1-4]:

  1. Inability to obtain peripheral IV access required for critical interventions or investigations.
  2. Long-term administration of vasoactive substances (e.g., norepinephrine/epinephrine infusions).
  3. Administration of high-concentration or potentially caustic medications (e.g., hypertonic saline, concentrated or large volumes of potassium chloride).
  4. High-pressure or large-volume infusions, such as massive transfusions in trauma patients with hemorrhagic shock.
  5. Emergent dialysis or plasmapheresis access in patients without established arteriovenous fistulas or other dialysis-capable access.
  6. Transvenous pacemaker placement.

Contraindications

Although there are many benefits of US-guided venous access, some contraindications and considerations should be kept in mind [3,4,7]:

  1. Presence of cellulitis, burns, massive edema, or injuries at or proximal to the proposed insertion sites.
  2. Other injuries, diseases, or anatomical distortions of the affected limb/site that may lead to complications during or after access (e.g., compartment syndrome, extravasation, bleeding from neoplasms, etc.).
  3. Risk of compromised vascular flow distal to the site.
  4. Coagulopathy (considered a relative contraindication).
  5. A capacitated patient declines to undergo the procedure after demonstrating an understanding of the risks and benefits as explained by the care team.

Equipment and Patient Preparation

While the materials and equipment required for peripheral IV access are very similar to those needed for central vascular access, we have separated them into two lists to highlight some key differences. Regardless of the procedure, adherence to hand hygiene practices and the universal use of personal protective equipment are absolutely essential for every procedure.

Equipment for Peripheral IV Access

  • Ultrasound machine equipped with a high-frequency linear probe.
  • Examination gloves.
  • Skin disinfectant (e.g., alcohol swabs, chlorhexidine swabs, povidone-iodine, etc.).
  • Occlusive ultrasound probe cover.
  • Sterile ultrasound gel.
  • Elastic tourniquet.
  • IV catheter.
  • IV securement device and dressing.
  • IV extension tubing and IV port.
  • Normal saline flush.
  • Sharps disposal device/container.
  • Stool or chair (recommended).
Figure 1 - Equipment for Peripheral IV Access

Equipment for Central Venous Access

  1. Ultrasound machine with a high-frequency linear probe.
  2. Sterile gloves.
  3. Eye protection.
  4. Central Venous Catheter Kit (if available), which often includes:
    • Sterile gown.
    • Face mask.
    • Bouffant or scrub cap.
    • Skin disinfectant swabs (e.g., chlorhexidine, povidone-iodine, etc.).
    • Vial of local anesthetic, needle, and syringe.
    • 18-gauge introducer needle and syringe.
    • #11-blade scalpel.
    • Gauze.
    • Guidewire.
    • Dilator(s).
    • Central venous catheter.
    • Sterile saline flush syringes.
    • Needle driver.
    • Suture.
    • Dressing.
    • Sharps disposal hub.
  5. Sterile occlusive ultrasound probe cover sheath.
  6. Sterile ultrasound gel.
  7. IV ports.

Patient Preparation

Proper patient preparation is essential to ensure the accuracy of line placement and minimize patient discomfort or complications. 

Introduction and Identification
Begin by introducing yourself to the patient and confirming their full name. 

Patient History and Consent
Inquire about any allergies, phobias, or a history of fainting during previous IV line procedures. Clearly explain the purpose, benefits, and potential risks of the procedure in simple terms. Once the patient or their next of kin fully understands the information, obtain verbal consent. Note that written consent is not required in emergency situations unless mandated by institutional policy.

Alleviating Anxiety
Address any patient concerns and provide reassurance to help alleviate fear or anxiety. Ensuring the patient is calm can significantly improve their experience and the procedure’s success.

Procedure Steps

Here, we will describe the procedural steps for both ultrasound-guided peripheral intravenous access and ultrasound-guided central vascular access. For each procedure, ensure that the ultrasound machine and probes are in good working order and that there is sufficient power or a reliable power source to successfully and safely complete the procedure. Ultrasound probes should be disinfected before and after each use to protect both patients and providers from exposure to bloodborne and other pathogens, even when sterile probe covers are used. For an overview of the procedural steps for ultrasound-guided peripheral IV access, please review the accompanying video.

Image Acquisition in Vascular Access Procedures

Optimizing the image of the target vessel is critical for procedural safety and success in ultrasound-guided vascular access. This section will describe the general principles and equipment needed to obtain and optimize target visualization.

The high-frequency linear ultrasound probe is most commonly used for vascular access procedures as it provides high-resolution images of superficial structures in the body (Figure 2). Although this resolution comes at the cost of limited penetration into deeper tissues, this limitation is rarely an issue due to specific factors influencing the appropriate depth of target vessels for cannulation, as discussed below.

Figure 2 - Linear Probe (transducer)

The next step is to ensure proper left-right probe orientation. This is accomplished prior to image acquisition by aligning the probe indicator on the ultrasound screen with the probe indicator on the linear probe itself. According to standard convention, the probe indicator on the device screen will appear as a dot, arrow, manufacturer logo, or other marking on the upper left side of the screen (Figure 3a).

Figure 3a - US Probe and Screen Markers

The image nearest the probe indicator on the screen corresponds to the signal emitted from the probe transducer head closest to the physical probe indicator, typically a raised marking or similar feature. A simple technique to confirm orientation involves applying a small amount of ultrasound gel to one side of the probe face, touching this area with a gloved finger, and observing where the movement appears on the screen (Video 1). Once the two markers are aligned, rightward movement on the screen will correspond to movement away from the probe indicator in physical space.

Once orientation is established, perform a survey scan of the site. After applying an elastic tourniquet (if peripheral IV access is being attempted), position the probe perpendicular to the long axis of the extremity or the anticipated course of the target vessel (Figure 4).

Figure 4 - positioning the probe perpendicular to the long axis

This generates a “transverse,” “short-axis,” or “cross-sectional” image of the vessel. If the screen appears too dark to delineate structures, increase the gain setting to brighten the image. Conversely, if the screen is too bright, decrease the gain setting. Vessels should appear as circular structures with a dark or “anechoic” center, indicating blood within the lumen that allows the ultrasound beam to pass through easily (Figure 5).

Figure 5 - increasing the gain setting to brighten the image

Several critical aspects of the target vessel must be assessed during imaging to ensure suitability for cannulation, including vessel type (venous vs. arterial), diameter, depth, patency, and proximity to other structures.

Vessel Assessment: Begin by verifying that the target is a vein. Veins have thinner walls compared to arteries and are compressible. Gentle pressure applied to the vein should cause the walls to collapse inward and meet, confirming its venous nature. Compression also ensures there is no intraluminal obstruction, such as a venous clot (Video 2).

Video 2 – applying pressure to the vessels

Next, assess the vessel’s depth using the depth markers displayed on the ultrasound screen, which typically indicate depth in centimeters. For example, a vessel aligned with the second hash mark from the top of the screen would be located at a depth of 2 cm from the skin surface (Figure 6).

Figure 6 - Measuring the depth of the vessel

Once the depth is measured, determine the vessel diameter, which is essential for selecting the appropriate catheter size for peripheral IV access. Finally, rotate the transducer 90 degrees to visualize the vessel in its long axis, ensuring that the target location is not near a branch point or valve.

Catheter Selection: In peripheral IV access, depth and diameter measurements determine the appropriate catheter size. Peripheral IV catheters vary in diameter (gauge), with smaller gauge numbers indicating larger catheter diameters (e.g., 16G is larger than 22G). A vessel diameter greater than 4 mm (0.4 cm) can accommodate an 18G or smaller catheter without occlusion. 

Figure 7 - Catheters

Catheters also come in various lengths, which affect their stability and suitability for deeper vessels. The depth of the target vessel determines the required catheter length, as longer catheters provide greater stability within the vein [2,3].

Figure 8 - Hypotenuse (needle track), [the image provided by authors]

The needle length required to reach the target vessel can be approximated using the Pythagorean theorem:

a2 + b2 = c2,

where c represents the needle track (hypotenuse. figure 8), a is the vessel depth, and b is the distance from the probe to the needle insertion point. For example, for a vessel 1.2 cm deep with a needle insertion point 1.2 cm distal to the probe, the calculation would be:

1.22 + 1.22 = c2,

resulting in c = 1.69 cm. A simpler method is to multiply the vessel depth by 1.4 (e.g., 1.2 cm × 1.4 = 1.68 cm). To ensure catheter stability within the vein, use the following formula to estimate the necessary catheter length:

Catheter Length = (Vein Depth × 1.4) × 3

This formula accounts for 1/3 of the catheter length reaching the vessel and 2/3 residing within the vein lumen. For example, a 6 cm catheter should not be used for vessels deeper than 1.6 cm.

For peripheral venous access, the following characteristics define an appropriate target vessel for US-guided peripheral IV access:

  • Easily compressible with light pressure applied using the ultrasound probe.
  • Follows a straight path as it travels proximally.
  • Lacks valves that would impede the passage of the cannula or flow after insertion.
  • Diameter greater than 0.4 cm.
  • Close to the skin surface, at a depth of less than 1.6 cm.

For central venous access, the same general principles apply. Regarding vessel diameter and depth, large-diameter vessels that are as superficial as possible are optimal. However, given the nature of these vessels in adult patients and the equipment used for central venous access, the exact parameters regarding diameter and depth mentioned for peripheral vein characteristics do not rigidly apply. Large-diameter vessels such as the internal jugular veins, subclavian veins, and femoral veins are preferred, and access should ideally be attempted at the point where the vessel is located as superficially as possible [4].

Regardless of whether peripheral or central IV access is utilized, the procedure under ultrasound guidance involves dynamically guiding the needle tip to prevent complications. Dynamic cannulation can be performed using either a transverse, out-of-plane approach or a longitudinal, in-plane approach. The transverse view, also known as the out-of-plane approach, is the most commonly used and involves visualizing the needle as a hyperechoic (bright) dot on the ultrasound screen. In contrast, the in-plane approach allows direct visualization of the entire needle length in a long-axis plane but is more challenging for novices, as the needle must remain within the ultrasound beam.

As the metallic needle within the catheter is hyperechoic, it appears as a white dot in the transverse plane and a long hyperechoic line in the longitudinal plane (Figure 9).

Figure 9 - the metallic needle within the catheter is hyperechoic, it appears as a white dot in the transverse plane and a long hyperechoic line in the longitudinal plane

In the transverse plane, it is critical to track the needle tip as it pierces the ultrasound beam, as the appearance of the needle looks the same regardless of its position along the beam. This tracking is achieved by alternating movements of the transducer and the needle. By “leading” with the transducer, then advancing the needle, the tip can be visualized first. Once the needle is seen, advancement should pause, and the transducer should slide slightly proximal up the vein where the needle is no longer visible, after which the needle can be advanced again (Figure 10). This alternating movement allows visualization of the tip as it progresses through the soft tissue and can be repeated until the vein is cannulated (Video 3).

Figure 10a - Walking down the vein: This sequence illustrates the process of "walking down the vein" as observed on an ultrasound. From left to right: the needle initially appears, then disappears, and later re-emerges deeper within the soft tissue before vanishing again. This phenomenon occurs due to the probe moving away, and when the needle reappears, it simply aligns with the ultrasound beam. Note that in real-time, the needle’s positional changes are more gradual than shown here; the figure above is a simplified representation of the concept (refer to the accompanying video for details). [The image was provided by authors].

Video 3 – Walking down the vein

Once the needle is visualized within the vein, the transducer can be rotated to ensure that the needle tip is within the vein lumen and has not pierced the back wall of the vessel. This visualization also allows for redirection of the needle before catheter insertion, ensuring smooth placement when the catheter is advanced off the needle (Video 4). For central venous catheters, a guidewire is inserted after confirming the needle’s position within the vein lumen.

Video 4 – provided by authors

After successfully inserting the IV line, blood return should be verified, and the catheter should be secured in place. As a final confirmation, flush the line. For peripheral IVs, place the ultrasound transducer proximally from the IV site, flush the line, and observe for turbulence or a “glitter artifact” caused by fluid rushing through the vein (Video 5).

Video 5 – provided by authors

This step confirms successful IV cannulation and can also assist in troubleshooting. If the “glitter” does not appear within the vein, the IV catheter is outside the vessel and unusable. For central lines, this confirmation can be performed by visualizing the “glitter” artifact in the right ventricle using the subxiphoid plane within three seconds of flushing the distal port of the line (Video 6).

Video 6 – Glitter Artifact [the video was provided by authors]

Step by Step Guide for US-Guided Peripheral IV Access [3,8]

  1. Verify the identity of the patient who is to undergo IV access and explain the procedure to the patient/healthcare surrogate (when possible).
  2. Position the ultrasound machine on the same side of the patient as the operator.
  3. Don examination gloves.
  4. Clean the ultrasound probe with institution-approved disinfectant.
  5. Remove gloves and replace with clean gloves.
  6. Position stool/chair and adjust the ultrasound machine for the best screen viewing when obtaining access.
  7. Apply an elastic tourniquet proximal to the site to be screened for potential access sites.
  8. Apply ultrasound gel to the target area and orient the probe perpendicularly to the patient’s extremity to obtain a transverse/short-axis view of the target vessels.
  9. Orient the probe indicator to match the orientation displayed on the ultrasound screen, with both conventionally indicating the patient’s right side (Figure 3a).
  10. Assess potential veins for appropriate depth, diameter, and patency.
  11. Veins should:
    • Be greater than or equal to 0.4 cm in diameter for an 18G catheter.
    • Be less than 1.6 cm in depth for a 6 cm length catheter.
    • Be easily compressible without evidence of clots, valves, or other obstructions to blood flow.
  12. Clean off ultrasound gel and release the tourniquet.
  13. Clean the selected site with skin disinfectant and allow it to air dry per manufacturer instructions.
  14. Set up supplies (prepare IV catheter, securement device, port, flush, and dressing).
  15. Cover the ultrasound probe with an occlusive cover.
  16. Avoid touching the head of the probe or the portion of the cover that will contact the patient’s skin.
  17. Reapply the tourniquet and ensure the patient’s arm remains in the appropriate position.
  18. Apply sterile ultrasound gel to the site.
  19. Do not touch the site with gloves or allow uncleaned materials/surfaces to come into contact with the site.
  20. If the site is potentially contaminated, remove the gel and clean the site again before attempting vascular access.
  21. Position the probe and locate the target vein again.
  22. At approximately a 45-degree angle, puncture the skin underneath the ultrasound probe head, observing on ultrasound for the needle tip in the subcutaneous tissue.
  23. Once the needle tip has been visualized, slide the probe proximally away from the needle tip.
  24. Once the needle tip is no longer visualized on ultrasound, carefully advance the needle in 1-2 mm increments until the needle tip returns into view on ultrasound.
  25. Repeat this alternating probe-needle advance until the needle has been advanced into the target vessel (Video 3).
  26. Decrease the angle of the needle as needed to continue advancing the needle in the alternating probe-needle manner within the vessel, keeping the needle tip in the center of the vessel lumen.
  27. Once the needle has been advanced several millimeters into the target vessel, anchor the hand holding the needle to ensure it does not advance further and lay down the ultrasound probe.
  28. Keeping the needle still, advance the catheter over the needle into the vessel.
  29. Once the catheter has been advanced, keep the catheter in place with the hand which advanced the catheter and use the other hand to carefully remove the needle.
  30. Ensure the safety needle capping mechanism on the needle has activated (if automatic upon needle removal from catheter) or activate the safety needle capping mechanism (if not designed to engage automatically) and dispose of the needle into a designated sharps container.
  31. Attach extension tubing and port to the catheter hub (some catheters come with the extension tubing and hub pre-attached).
  32. Clean any remaining ultrasound gel or blood from the access site and secure the catheter with an occlusive dressing.
  33. Attach a saline flush to the hub.
  34. If any air remains in the catheter extension tubing (if applicable), be sure to aspirate any air prior to attempting to flush the line.
  35. Retrieve the ultrasound probe and place it along the vessel proximal on the extremity to the catheter.
  36. After confirming the absence of air in the catheter and extension tubing, flush several cc’s of crystalloid solution through the catheter.
  37. If the catheter is in the correct position and functioning correctly, a “glitter” artifact effect should be visualized within several seconds of pushing the fluid through the catheter (Video 6).
  38. Dispose of supplies in appropriate containers and clean the ultrasound probe with disinfectant wipes.
  39. Remove gloves and wash hands.
  40. Document the access site in the patient’s chart, including site location, catheter gauge, time placed, and operator placing the line.
  41. Ensure you and your team frequently assess the site and extremity for evidence of extravasation, hematoma formation, or other complications.

Step by Step Guide for US-Guided Central Venous Access [4,9]

  1. Verify the identity of the patient who is to undergo IV access and explain the procedure to the patient/healthcare surrogate (when possible).
  2. Position the ultrasound machine on the opposite side of the patient as the operator in the operator’s line of sight.
  3. Don examination gloves.
  4. Clean the ultrasound probe with institution-approved disinfectant.
  5. Remove gloves and replace with clean gloves.
  6. Apply ultrasound gel to the target area and orient the probe perpendicularly to the patient’s extremity to obtain a transverse/short-axis view of the target vessels.
  7. Orient the probe indicator to match the orientation displayed on the ultrasound screen, with both conventionally indicating the patient’s right side (Figure 3a).
  8. Assess potential veins for appropriate depth, diameter, and patency:
  9. Veins should:
    • Be greater than or equal to 0.4 cm in diameter for an 18G catheter.
    • Be less than 1.6 cm in depth for a 6 cm length catheter.
    • Be easily compressible without evidence of clots, valves, or other obstructions to blood flow.
  10. Clean off ultrasound gel.
  11. Clean the selected site with skin disinfectant and allow it to air dry per manufacturer instructions.
  12. Open the central venous catheter kit (or, if unavailable, establish a sterile field upon which to place sterile equipment).
  13. Don eye protection, face mask, and bouffant/scrub cap.
  14. Don a sterile gown and gloves.
  15. Drape the patient in a sterile fashion.
  16. Place the dominant hand within a sterile ultrasound probe cover (if rubber bands to secure the sheath to the probe are included, consider applying rubber bands around the thumb of the dominant hand before placing the hand within the sheath).
  17. Apply sterile gel to the inside of the sheath, which will contact the ultrasound probe head.
  18. Have an assistant pass the linear probe and grab the probe head with the dominant hand surrounded by the ultrasound probe sheath.
  19. Carefully extend the sheath around the probe. Once able, ask an assistant to grab the open end of the probe sheath and pull it toward them along the probe’s wire until it is well away from the sterile field. The assistant can gently release the probe wire now covered in the sheath, being careful not to let the contaminated end of the probe cover touch the sterile field.
  20. Apply the rubber bands (if applicable) to the head of the probe and smooth any air bubbles or irregularities which may have formed along the transducer surface while inserting the probe.
  21. Draw up several cc’s of local anesthetic into a syringe.
  22. Apply sterile ultrasound gel to the target site and confirm there has been no change in positioning of the target vessel during setup.
  23. Inject the local anesthetic into the skin and along the track of the needle to the target vessel, being sure to aspirate before each injection.
  24. It is recommended that the injection of the local anesthetic be performed under active ultrasound guidance to minimize the chance of accidental injection into the vessel and to confirm the anesthetic is applied along the intended tract of the needle.
  25. Ensure that air bubbles have been removed from the local anesthetic solution prior to injection, as these air bubbles will distort visualization of the target vessel area due to scattering of the ultrasound beam as it comes into contact with air.
  26. While the local anesthetic takes effect, flush the lumens of the catheter with saline to prevent the introduction of air into the patient’s vasculature and test that the guidewire feeds smoothly and is free of kinks or defects.
  27. With the introducer needle at an approximately 45-degree angle, puncture the skin underneath the ultrasound probe head, observing on ultrasound for the needle tip in the subcutaneous tissue.
  28. Once the needle tip has been visualized, slide the probe proximally away from the needle tip.
  29. Once the needle tip is no longer visualized on ultrasound, carefully advance the needle in 1-2 mm increments until the needle tip returns into view on ultrasound (Figure 8).
  30. Repeat this alternating probe-needle advance until the needle has been advanced into the target vessel, pulling back on the needle plunger to aspirate blood upon entry into the vessel.
  31. Decrease the angle of the needle as needed to continue advancing the needle in the alternating probe-needle manner within the vessel, keeping the needle tip in the center of the vessel lumen.
  32. Once the needle has been advanced several millimeters into the target vessel, anchor the hand holding the needle to ensure it does not advance further and lay down the ultrasound probe.
  33. Keeping the needle still, lay down the ultrasound probe, remove the syringe from the needle, and retrieve the guidewire.
  34. Advance the guidewire through the introducer needle approximately 20 cm, ensuring that it passes freely without resistance. If resistance is encountered, stop advancing immediately and assess the situation.
  35. Keeping one hand on the guidewire at all times, withdraw the introducer needle over the guidewire and place it in a sharps disposal device or bin.
  36. Confirm that the guidewire is in the target vessel using ultrasound to visualize the guidewire in the vessel in long-axis (Figure 9).
  37. Place gauze nearby the guidewire insertion site for use in the upcoming step.
  38. Place the dilator over the guidewire and advance it toward the skin, stopping several centimeters above the skin.
  39. Using the scalpel, make a small linear incision with the blade directed away from the guidewire and the patient. Consider placing gauze over the site after the incision to minimize bleeding.
  40. Using the dominant hand, insert the dilator to the approximate depth of the vessel visualized on ultrasound, using the other hand to hold the guidewire.
  41. It is recommended to use a twisting motion while advancing the dilator with the hand gripping the dilator just above the patient’s skin.
  42. Ensure that the guidewire remains stationary during dilatory insertion.
  43. Remove the dilator over the guidewire and thread the central venous catheter over the guidewire.
  44. Advance the catheter into the vessel over the guidewire while keeping one hand on the guidewire at all times.
  45. The guidewire should emerge from the distal port of the catheter (typically marked with a brown hub and located in the center of the available ports).
  46. Once the catheter has been placed at the appropriate depth into the target vessel, aspirate blood using a syringe from all ports to ensure patency.
  47. Flush all ports with saline to minimize the chance of clotting.
  48. Use the needle driver and suture to secure the line in place.
  49. Clean the site once more and apply an institution-approved antimicrobial dressing.
  50. If the line was placed in an internal jugular or subclavian vein site, obtain a post-procedural chest radiograph to confirm appropriate placement and assess for complications (e.g., pneumothorax).
Figure 9 - Guide-wire in the vessel - long axis view

Complications

Ultrasound-guided venous access, while generally safer than traditional landmark techniques, still carries potential complications, both for peripheral and central line placement.

Complications of US-Guided Peripheral IV Access [1-3,8]

Infiltration/Extravasation: This is a common complication where IV fluid or medication leaks into the surrounding tissue instead of flowing into the vein. It is a leading cause of catheter failure and may occur more frequently with deep brachial veins compared to other antecubital veins. Using a longer catheter can help minimize the risk of infiltration.

Catheter Dislodgement: Catheter dislodgement occurs when the catheter moves out of the vein, leading to loss of venous access and potential extravasation. This complication is more common with deep veins compared to superficial veins. To reduce the risk, it is essential to ensure that a sufficient length of the catheter is properly positioned within the vessel.

Thrombophlebitis: Thrombophlebitis refers to the inflammation of the vein, which may occur during or after IV placement.

Infection: Although studies have shown no increased infection rates with ultrasound guidance compared to traditional methods, the risk of infection remains. Using sterile gel and adhering to proper cleaning techniques can significantly reduce this risk.

Damage to Adjacent Structures: There is a risk of damaging nearby structures, such as arteries and nerves, during peripheral IV placement. This risk is heightened when using deep veins, which are often located closer to these critical structures.

Posterior Vessel Wall Puncture: The short-axis technique, commonly used during ultrasound-guided IV access, has been associated with a higher risk of puncturing the posterior (back) wall of the vessel.

Hematoma: Bleeding and hematoma formation can occur as a result of vein trauma during catheter placement.

Premature Catheter Failure (PCF): Premature catheter failure occurs when the catheter fails within 24 hours of placement. Studies suggest that PCF rates are higher in ultrasound-guided cannulations compared to traditional methods. Common causes include infiltration, dislodgement, and thrombophlebitis.

Complications of Ultrasound-Guided Central Venous Catheter (CVC) Access [4,9,10]

Arterial Puncture/Cannulation: Accidental puncture or cannulation of an artery, such as the carotid artery during internal jugular vein access, is a serious complication. This risk can be mitigated by using real-time ultrasound guidance and ensuring careful visualization of surrounding structures.

Hematoma: Bleeding and hematoma formation are potential complications during central venous catheter placement, especially if there is accidental puncture of surrounding tissues.

Pneumothorax: A collapsed lung (pneumothorax) is a known complication, particularly during subclavian vein access. Ensuring proper technique and real-time imaging can help reduce this risk.

Hemothorax: Bleeding into the pleural space (hemothorax) may occur during central venous access, especially if there is inadvertent damage to vascular structures near the pleural cavity.

Infection: Catheter-related bloodstream infections are a significant risk associated with central lines. Adherence to strict aseptic technique, including the use of sterile drapes, gloves, and probe covers, is essential to minimize this risk.

Thrombosis: Deep vein thrombosis and catheter-related bloodstream infections can occur as a result of CVC placement. Proper placement, routine monitoring, and prompt intervention are critical in reducing this risk.

Nerve Injury: There is a risk of nerve damage, such as brachial plexus injury, during internal jugular vein catheterization. Careful visualization of anatomical landmarks using ultrasound is critical to avoid this complication.

Catheter Malposition: The catheter may be unintentionally placed in an incorrect location, leading to functional and clinical complications. Real-time imaging during and after placement can ensure proper positioning of the catheter.

Air embolism: It is a rare but serious complication associated with both peripheral and central vein catheterization, which can cause significant neurological deficits and seizures if not promptly diagnosed and treated. The pathophysiology involves air entering the venous system due to a pressure gradient between the atmosphere and the veins, which can occur during catheter insertion, maintenance, or removal. The risk of air embolism is heightened by improper patient positioning. In cases of massive air embolism, immediate interventions such as resuscitation, positioning the patient in the left lateral decubitus and Trendelenburg position, and using hyperbaric oxygen therapy or extracorporeal membrane oxygenation can be life-saving.

Hints and Pitfalls

Universal safety precautions are critical for every procedure. This includes the consistent use of personal protective equipment (PPE) and cleaning all equipment before and after use. These practices are essential to protect both the operator and the patient from harm, including the risk of infections or cross-contamination.

Preparation is paramount to ensuring procedural success and minimizing complications. Proper assessment of the target vessel, including its depth, diameter, and patency, along with setting up the necessary equipment in advance, significantly increases the chances of success during cannulation. Needle tip visualization is also crucial throughout the procedure to prevent iatrogenic injuries caused by inadvertently advancing the needle tip into non-target structures near the vessel.

If a cannulation attempt fails or if the intravenous (IV) line fails due to infiltration, subsequent attempts should ideally be made at a different site to avoid cumulative damage to the same area. If a new site cannot be used, attempts should occur proximal to the initial site.

Strategies to Reduce Complications [1-3, 7-10]

Adequate training is a cornerstone of safe and successful ultrasound-guided venous access. Providers must be proficient in real-time ultrasound guidance techniques, which allow precise needle advancement and proper placement. Additionally, sterile technique is essential during all stages of the procedure, including the use of sterile gel and probe covers to minimize infection risk.

Choosing the appropriate vein for cannulation is another key strategy to reduce complications. This decision should be based on careful vein selection, including evaluating its accessibility and suitability for the intended catheter size. Proper catheter length and size selection are equally important, with tools like the Pythagorean theorem aiding in determining the optimal catheter length for stable placement within the vessel.

Visualization of the needle tip during insertion is vital to avoid injury to surrounding structures. The long-axis approach can provide continuous visualization of the needle tip, ensuring accurate placement within the vessel lumen. After catheter placement, ultrasound can confirm the catheter’s position and patency, reducing the risk of complications such as malposition or infiltration.

Post-procedural monitoring is just as important as the procedure itself. Regular assessment of the insertion site is necessary to detect early signs of infection, thrombophlebitis, or other complications, allowing for timely intervention if needed.

Special Patient Groups

Pediatrics

US-guided venous access in pediatric patients has been shown to significantly enhance the success rates and reduce complications associated with vascular access procedures. A retrospective analysis of 1028 US-guided central vascular access procedures in children demonstrated a high success rate of 97.2%, with the left brachiocephalic vein showing a higher success rate than the right [11]. The integration of ultrasound guidance in pediatric venous access procedures is associated with improved outcomes, emphasizing its role as a preferred method in clinical practice.

Geriatrics

US-guided venous access in geriatric patients has been shown to be a highly effective and safe method for catheter placement. The use of ultrasound guidance significantly reduces failure (success rate of 96.36%) and complication rates (7.27%) [12]. US-guided peripherally inserted central catheter insertion in elderly patients also reported high success rate, with minimal complications [13]. The use of ultrasound guidance for internal jugular vein catheterization further supports its efficacy in reducing failure and complication rates for central venous port placement [14]. Overall, the integration of ultrasound guidance in venous access procedures for geriatric patients enhances safety, reliability, and patient outcomes, making it a valuable tool in the management of this vulnerable population [12-14].

Pregnant patients

US-guided venous access provides significant benefits for pregnant patients, particularly by reducing complications and improving procedural success. Real-time ultrasonographic imaging enables clear visualization of target vessels, which is especially critical in cases of challenging anatomy during pregnancy [15]. This approach aligns with the growing adoption of point-of-care ultrasound (POCUS) to enhance success rates in both peripheral and central venous catheterization. By improving patient safety and minimizing complications, ultrasound guidance has become an essential tool for optimizing venous access procedures and ensuring safer care for pregnant patients [16].

Authors

Picture of Zackary Funk

Zackary Funk

Picture of Petra Duran-Gehring

Petra Duran-Gehring

Petra Duran-Gehring M.D., graduated from medical school at LSU Health Sciences Center in New Orleans, and completed her residency in emergency medicine at the University of Florida College of Medicine – Jacksonville. She achieved certification through the American Registry of Diagnostic Medical Sonographers and founded the emergency ultrasound program for the department of emergency Medicine at UFCOMJ. She is a nationally recognized leader in emergency ultrasound education and research, including serving as co-director of the ACEP Ultrasound Management Course, and director for the SEMPA Ultrasound Course. She has lectured throughout the country, and has received numerous teaching awards. When not teaching ultrasound, she loves spending time with her husband and three young sons.

Listen to the chapter

References

  1. Duran-Gehring P. Ultrasound-Guided IV Access. The Essential Emergency Ultrasound Course; 2019. Accessed August 5, 2023.
  2. Duran-Gehring P, Bryant L, Reynolds JA, Aldridge P, Kalynych CJ, Guirgis FW. Ultrasound-Guided Peripheral Intravenous Catheter Training Results in Physician-Level Success for Emergency Department Technicians. J Ultrasound Med. 2016;35(11):2343-2352. doi:10.7863/ultra.15.11059
  3. Gottlieb M, Sundaram T, Holladay D, Nakitende D. Ultrasound-Guided Peripheral Intravenous Line Placement: A Narrative Review of Evidence-based Best Practices. West J Emerg Med. 2017;18(6):1047-1054. doi:10.5811/westjem.2017.7.34610
  4. Leung J, Duffy M, Finckh A. Real-time ultrasonographically-guided internal jugular vein catheterization in the emergency department increases success rates and reduces complications: a randomized, prospective study. Ann Emerg Med. 2006;48(5):540-547. doi:10.1016/j.annemergmed.2006.01.011
  5. Jacobson AF, Winslow EH. Variables influencing intravenous catheter insertion difficulty and failure: an analysis of 339 intravenous catheter insertions. Heart Lung. 2005;34(5):345-359. doi:10.1016/j.hrtlng.2005.04.002
  6. Au AK, Rotte MJ, Grzybowski RJ, Ku BS, Fields JM. Decrease in central venous catheter placement due to use of ultrasound guidance for peripheral intravenous catheters. Am J Emerg Med. 2012;30(9):1950-1954. doi:10.1016/j.ajem.2012.04.016
  7. Shokoohi H, Armstrong P, Tansek R. Emergency department ultrasound probe infection control: challenges and solutions. Open Access Emerg Med. 2015;7:1-9. Published 2015 Jan 5. doi:10.2147/OAEM.S50360
  8. Blanco P. Ultrasound-guided peripheral venous cannulation in critically ill patients: a practical guideline. Ultrasound J. 2019;11(1):27. Published 2019 Oct 17. doi:10.1186/s13089-019-0144-5
  9. Saugel B, Scheeren TWL, Teboul JL. Ultrasound-guided central venous catheter placement: a structured review and recommendations for clinical practice. Crit Care. 2017;21(1):225. Published 2017 Aug 28. doi:10.1186/s13054-017-1814-y
  10. Parienti JJ, Mongardon N, Mégarbane B, et al. Intravascular Complications of Central Venous Catheterization by Insertion Site. N Engl J Med. 2015;373(13):1220-1229. doi:10.1056/NEJMoa1500964
  11. D’Alessandro P, Siffredi JI, Redondo Pertuz E, et al. Retrospective analysis of 1028 ultrasound-guided central vascular access in neonates and children. J Vasc Access. Published online September 26, 2024. Doi:10.1177/11297298241278385
  12. Sun X, Zhang Y, Yang C, et al. Ultrasound-guided totally implantable venous access device through the right innominate vein in older patients is safe and reliable. Geriatr Gerontol Int. 2019;19(3):218-221. doi:10.1111/ggi.13611
  13. Nakano Y, Kondo T, Murohara T, Yamauchi K. Option of Using Peripherally Inserted Central Catheters in Elderly Patients With Dementia: An Observational Study. Gerontol Geriatr Med. 2020;6:2333721420906922. Published 2020 Feb 18. doi:10.1177/2333721420906922
  14. Canfora A, Mauriello C, Ferronetti A, et al. Efficacy and safety of ultrasound-guided placement of central venous port systems via the right internal jugular vein in elderly oncologic patients: our single-center experience and protocol. Aging Clin Exp Res. 2017;29(Suppl 1):127-130. doi:10.1007/s40520-016-0680-9

Reviewed and Edited By

Picture of Arif Alper Cevik, MD, FEMAT, FIFEM

Arif Alper Cevik, MD, FEMAT, FIFEM

Prof Cevik is an Emergency Medicine academician at United Arab Emirates University, interested in international emergency medicine, emergency medicine education, medical education, point of care ultrasound and trauma. He is the founder and director of the International Emergency Medicine Education Project – iem-student.org, chair of the International Federation for Emergency Medicine (IFEM) core curriculum and education committee and board member of the Asian Society for Emergency Medicine and Emirati Board of Emergency Medicine.

Arterial Blood Gas Sampling (2025)

~ iEM Education Project Team ~ Leave a comment

by Gan Kiat Kee & Arif Alper Cevik

Authors
Listen

Introduction

Arterial blood gas (ABG) sampling is a critical procedure performed in the emergency department (ED) that involves obtaining blood from a peripheral artery to assess a patient’s respiratory and metabolic status. This technique is essential for diagnosing and managing various acute conditions, particularly in critically ill patients. The common sites for ABG sampling include the radial, brachial, femoral, and dorsalis pedis arteries. The radial artery is often preferred due to its accessibility and the presence of collateral circulation, which minimizes the risk of complications [1]. ABG sampling can be performed via a single percutaneous needle puncture or through an indwelling catheter for repeated measurements, which is particularly useful in ongoing monitoring of patients with unstable conditions [2].

The analysis of ABG provides vital information regarding the patient’s acid-base balance and respiratory function. Key parameters measured include the partial pressures of oxygen (PaO2) and carbon dioxide (PaCO2), pH, and bicarbonate (HCO3) levels. These measurements are crucial for evaluating the efficacy of gas exchange in the lungs and the metabolic status of the patient [3]. For instance, a low pH coupled with elevated PaCO2 may indicate respiratory acidosis, while a low HCO3 may suggest metabolic acidosis. Additionally, advanced blood gas analyzers can provide further insights by measuring total hemoglobin (tHb), oxyhemoglobin saturation (HbO2), and dysfunctional hemoglobins such as methemoglobin (MetHb) and carboxyhemoglobin (COHb), which are particularly relevant in cases of carbon monoxide poisoning or other hemoglobinopathies [3].

The ability to interpret ABG results is an essential skill for healthcare professionals, particularly in emergency settings where rapid decision-making is crucial. Medical trainees are encouraged to gain proficiency in ABG sampling and interpretation under supervision, as these skills are fundamental to the effective management of patients experiencing respiratory distress, shock, or metabolic derangements [1].

Figure 1 - An example of an arterial blood gas analysis result (Courtesy of Gan Kiat Kee)

Indications

ABG sampling is primarily indicated for evaluating the adequacy of oxygenation and ventilation in patients. By measuring the partial pressures of oxygen (PaO2) and carbon dioxide (PaCO2), healthcare providers can assess respiratory function and the effectiveness of gas exchange in the lungs. For instance, a low PaO2 may indicate hypoxemia, necessitating immediate intervention, while elevated PaCO2 can signify respiratory failure or impaired ventilation [4]. This immediate assessment is crucial in emergencies such as acute respiratory distress or exacerbations of chronic obstructive pulmonary disease (COPD), where timely identification of respiratory compromise can significantly influence patient outcomes [5].

In addition to evaluating oxygenation and ventilation, ABG sampling is essential for identifying and monitoring acid-base disturbances. The measurement of pH, PaCO2, and bicarbonate (HCO3) levels provides critical information regarding the patient’s metabolic and respiratory status. For example, an acidic pH coupled with elevated PaCO2 may suggest respiratory acidosis, commonly seen in conditions such as acute asthma attacks or severe pneumonia [6]. Conversely, metabolic acidosis may be indicated by a low pH with normal or low PaCO2 levels, often observed in patients with diabetic ketoacidosis or renal failure. Monitoring these parameters can guide therapeutic decisions and help clinicians tailor interventions to restore acid-base balance effectively [6].

Furthermore, ABG sampling plays a significant role in detecting and quantifying abnormal hemoglobin levels, such as methemoglobin (MetHb) and carboxyhemoglobin (COHb). These conditions can arise from exposure to certain chemicals or gases, and their identification is critical in emergency settings. For instance, elevated COHb levels indicate carbon monoxide poisoning, which requires immediate treatment [7]. The ability to quickly diagnose such abnormalities through ABG sampling can be life-saving, particularly in cases of suspected toxic exposure.

Lastly, ABG sampling is invaluable in assessing the response to therapeutic interventions, particularly in hypoxic patients receiving oxygen therapy. By comparing pre- and post-intervention ABG values, clinicians can evaluate the effectiveness of treatments and make necessary adjustments to optimize patient care. In situations where venous sampling is not feasible due to the patient’s condition or the urgency of the situation, ABG sampling serves as a critical alternative for obtaining essential blood gas information [4].

Contraindications

Certain contraindications must be considered to ensure patient safety and the accuracy of results. One primary contraindication is the presence of a known deficiency in collateral circulation, which can be assessed using the modified Allen’s test. An abnormal result indicates insufficient blood flow to the hand, increasing the risk of ischemia if an artery is punctured [8-10]. Therefore, performing an ABG in such cases could lead to serious complications, including limb ischemia or necrosis.

In addition to collateral circulation issues, the presence of local infections at the puncture site is another significant contraindication. An infected site can introduce pathogens into the bloodstream, leading to systemic infections or further complications for the patient [11]. Moreover, anatomical abnormalities such as full-thickness burns, arteriovenous fistulas, stents, or vascular grafts at the puncture site can complicate the procedure and increase the risk of complications. These malformations may alter normal blood flow patterns or make it difficult to locate the artery accurately, which can lead to unsuccessful attempts or injury to surrounding structures [8-10].

Severe peripheral vascular disease, including conditions like Buerger’s disease or limb ischemia, also serves as a contraindication for ABG sampling. In patients with these conditions, blood flow to the extremities is already compromised, and the additional trauma of arterial puncture could exacerbate ischemic symptoms [12]. Lastly, patients suffering from active Raynaud syndrome should be excluded from ABG sampling, as the procedure could trigger or worsen their vasospastic episodes, leading to further complications [13].

Some conditions may pose relative contraindications [8-10] to this procedure. Patients with Raynaud disease may experience exacerbated symptoms during and after the puncture, potentially resulting in complications such as ischemia or necrosis at the site of the arterial puncture [14]. Furthermore, even in the absence of spasm, individuals with a history of Raynaud disease may have altered peripheral vascular function, increasing the likelihood of complications during ABG sampling.

Another important relative contraindication is the presence of poor peripheral perfusion, which can severely affect the ability to obtain an adequate blood sample. In patients with compromised perfusion, such as those in shock or with peripheral vascular disease, the risk of inadequate sampling and subsequent complications at the puncture site is elevated. Poor perfusion can lead to difficulties in locating the artery, increasing the risk of multiple punctures and subsequent tissue trauma [15]. Thus, clinicians must assess the patient’s peripheral circulation before proceeding with ABG sampling to avoid unnecessary complications.

Additionally, patients with supratherapeutic anticoagulation or those receiving thrombolytic agents, such as streptokinase or tissue plasminogen activator, represent another group with relative contraindications for ABG sampling [16]. The risk of bleeding complications in these patients is significantly heightened due to their altered coagulation status. Similarly, individuals with existing coagulopathy should be approached with caution, as the likelihood of significant bleeding increases, which could lead to hematoma formation or other vascular complications. In these cases, the clinical necessity of obtaining an ABG sample must be carefully weighed against the potential risks involved, and alternative methods of assessment should be considered if appropriate.

Equipment and Patient Preparation

Equipment

The equipment used in ABG sampling includes the following [16]:

  • Gloves: Non-sterile gloves may be used, but it is essential to avoid touching the puncture site after the area has been cleaned.
  • Syringe for Sampling: A standard syringe with a 25-gauge needle and a 3-mL capacity is preferred. Using a higher-capacity syringe may reduce maneuverability, while smaller needles may increase the risk of traumatic hemolysis, potentially affecting the accuracy of hemoglobin and potassium measurements. A 23-gauge needle may also be used.
  • Lithium Heparin: Aspirate 1-2 mL of lithium heparin (1000 U/mL) into the syringe through the needle and then expel it. Leave the plunger depressed to allow arterial blood flow to fill the syringe.
  • Pre-Heparinized ABG Syringe (Alternative): Many ABG kits include a prefilled heparinized syringe with features like a protective needle sleeve and a syringe cap. Some syringe models have vented plungers that enable presetting a specific blood volume; for these, the plunger is positioned midway in the syringe before the puncture and not pulled back during the procedure. Expel the prefilled heparin before repositioning the vented plunger at the 2-mL mark.
  • Antiseptic Skin Solution: Commonly used solutions include chlorhexidine, povidone-iodine, or 70% isopropyl alcohol.
  • Needle and Syringe for Local Anesthesia (Optional): A 25-gauge needle with a syringe and 1% lidocaine hydrochloride without epinephrine may be used for local anesthesia if needed.
  • Sterile Gauze and Adhesive Bandage: Sterile gauze (2 × 2 inches or 5 × 5 cm) is used to cover the puncture site, secured with an adhesive bandage after sample collection.
  • Syringe Cap: Usually included in ABG kits to seal the syringe after sampling.
  • Sharps Container: A container specifically designed for the safe disposal of needles and other sharp objects.
  • Ice Bag: A bag with crushed ice to transport the sample to the laboratory if point-of-care analysis is unavailable.
  • Non-Sterile Apron: Optional protective clothing to maintain hygiene during the procedure.
  • Rolled Towel: Used to position the hand optimally for the procedure.

Site Selection

Arterial blood gas sampling requires selecting an appropriate site for puncture based on accessibility, patient tolerance, and anatomical considerations. Below are the common sites used for ABG sampling [17]:

Radial Artery
The radial artery is the preferred site for ABG sampling due to its superficial location, good collateral blood supply, and better patient tolerance. It is located medial to the radial styloid process and lateral to the flexor carpi radialis tendon, approximately 2-3 cm proximal to the ventral surface of the wrist crease. The artery can be palpated between the styloid process of the radius and the flexor carpi radialis tendon with the wrist extended.

Radial Artery - Resource: Wikimedia Commons - https://commons.wikimedia.org/wiki/File:Gray528.png

Brachial Artery
The brachial artery is harder to access due to its deeper location compared to the radial artery. It is best identified in the antecubital fossa, medial to the biceps tendon, with the shoulder abducted, elbow extended, and the forearm supinated with the palm facing upward. The needle is typically inserted at a 30° angle just above the elbow crease. Higher up, the artery can also be palpated in the groove between the biceps and triceps tendons. The basilic vein and brachial nerve are located in close proximity to this artery.

Brachial Artery - Resource: Wikimedia Commons - https://commons.wikimedia.org/wiki/File:Brachial_a.png

Femoral Artery
The femoral artery is ideal in cases where the radial and brachial arteries are inaccessible. It is located in the midline between the symphysis pubis and the anterior superior iliac crest, approximately 2-4 cm distal to the inguinal ligament. The artery can be palpated just below the midpoint of the inguinal ligament with the lower limb extended and the patient in a supine position. Needle insertion is performed just below the inguinal ligament at a 90° angle. The femoral artery lies medial to the femoral nerve and lateral to the femoral vein.

Femoral Artery - Resource: Wikimedia Commons - https://commons.wikimedia.org/wiki/File:Femoral-artery-grays-illustrations.jpg

Dorsalis Pedis Artery
The dorsalis pedis artery is a less commonly used site for ABG sampling. It can be palpated lateral to the extensor tendon at the midfoot level. This site is generally reserved for specific clinical scenarios where other arteries are not accessible.

Dorsalis Pedis Artery - Resource: Wikimedia Commons - https://commons.wikimedia.org/wiki/File:Art%C3%A8res_de_la_face_dorsale_du_pied.jpg

Each site has its unique anatomical landmarks and considerations, which should be carefully evaluated to ensure accuracy and minimize complications during the procedure.

Patient Preparation

Proper patient preparation is essential to ensure the accuracy of radial artery blood gas sampling and minimize patient discomfort or complications. Below are the key steps to prepare the patient for the procedure [16,17]:

Introduction and Identification
Begin by introducing yourself to the patient and confirming their full name. Verify that the details on the laboratory form match the patient’s identity to prevent errors.

Patient History and Consent
Inquire about any allergies, phobias, or a history of fainting during previous injections or blood collection. Clearly explain the purpose, benefits, and potential risks of the procedure in simple terms. Once the patient or their next of kin fully understands the information, obtain verbal consent. Note that written consent is not required unless mandated by institutional policy.

Alleviating Anxiety
Address any patient concerns and provide reassurance to help alleviate fear or anxiety. Ensuring the patient is calm can significantly improve their experience and the procedure’s success.

Procedure Steps

The following steps outline the procedure for radial artery blood gas sampling, as recommended by W.H.O. guidelines [16,17]:

Patient Introduction and Identification
Approach the patient, introduce yourself, and confirm the patient’s full name. Verify the details on the laboratory form to ensure accurate identification.

Patient Positioning
Place the patient in a comfortable supine position on a firm surface. For radial artery sampling, ensure the arm is resting comfortably with the forearm supinated and the wrist dorsiflexed at approximately 40°. A rolled towel or gauze roll can be placed under the wrist to improve comfort and elevate the radial artery to a more superficial position. Avoid excessive wrist extension to prevent interference from flexor tendons, which could make pulse detection challenging.

Assess Collateral Circulation
Perform a modified Allen test to assess collateral circulation of the radial artery. If the test fails, repeat it on the other hand. Once an adequate site is identified, note the anatomical landmarks for accurate needle placement. If re-palpation is required, ensure sterile gloves are worn.

  • Preparation of Equipment and Work Area
    Perform hand hygiene, prepare a clean work area, and gather all necessary equipment. Don an impervious gown or apron and face protection if there is a risk of blood exposure.

  • Site Disinfection
    Disinfect the chosen puncture site using an antiseptic skin solution such as chlorhexidine or povidone-iodine. Allow the area to air dry completely before proceeding.

  • Needle and Syringe Assembly
    If the needle and syringe are not preassembled, prepare them by attaching the heparinized syringe to the needle and setting the syringe plunger to the required fill level recommended by the laboratory.

  • Needle Insertion
    Hold the syringe and needle like a dart, with the needle bevel facing upward. Use your index finger to palpate the radial pulse, then inform the patient about the puncture. Insert the needle at a 30º–45º angle approximately 1 cm distal to the palpating finger to avoid contamination of the puncture site.

  • Blood Collection
    Advance the needle into the radial artery until a flashback of blood is observed. Allow the syringe to fill passively with 2–3 mL of arterial blood without pulling back the plunger.

  • Needle Withdrawal and Hemostasis
    After withdrawing the required amount of arterial blood, remove the needle while simultaneously applying firm pressure to the puncture site with sterile gauze. Maintain pressure until hemostasis is achieved. For patients without anticoagulation or coagulopathy, this typically takes 3–5 minutes, while anticoagulated patients or those with bleeding disorders or hypertension may require up to 10–15 minutes of continuous pressure. Avoid checking the puncture site prematurely, as this can increase the risk of hemorrhage or hematoma formation. 

  • Needle Safety and Specimen Handling
    Activate the needle safety mechanism to cover the needle or use a one-hand scoop technique to recap it. Dispose of the needle safely in a sharps container.

  • Sample Preparation
    Expel air bubbles from the syringe, cap it, and roll the specimen gently between your hands to mix it without compromising the sample’s integrity. Cap the syringe securely to prevent air contamination or leakage during transport.

  • Labeling and Transport
    Label the sample syringe appropriately and place it in a container with ice to preserve the sample. Transport it immediately to the laboratory, ensuring proper handling protocols are followed. Adhere to the recommended time frames for sample analysis to ensure accurate results:

    • For samples held at 4°C: Analysis should be conducted within 60 minutes.

    • For samples held at room temperature: Analysis should be conducted within 15 minutes.

  • Cleanup and Hygiene
    Dispose of all used materials and personal protective equipment in accordance with hospital protocols. Remove gloves and wash hands thoroughly with soap and water or use an alcohol-based hand rub.

  • Patient Reassessment
    Check the puncture site for ongoing bleeding or other complications. Apply additional pressure if necessary and thank the patient for their cooperation.

  • Special Considerations
    In critically ill or unresponsive patients, explain the procedure to family members or next of kin if possible. Additionally, minimize air bubbles in the sample as they can distort gas readings by altering PaO2 and PaCO2 levels.

  • Use of Local Anesthesia (Optional)
    Local anesthesia, such as lidocaine HCl 1% without epinephrine, may be administered subcutaneously to reduce discomfort [18, 19]. However, this step is not always necessary, as the pain from administering the anesthetic is often comparable to the pain of the procedure itself. If used, 0.5–1 mL of anesthetic should be injected to form a small dermal papule at the puncture site. Care should be taken not to distort the anatomy, and the clinician should aspirate before injection to confirm the needle is not inside a blood vessel.

Post Procedure Care and Recommendations

After completing the blood sampling procedure, appropriate post-procedure care is essential to ensure patient safety and minimize complications [16,17].

Closely monitor the patient for any new symptoms, such as changes in skin color, persistent or worsening pain, active bleeding, impaired limb movement, or altered sensation. Monitoring is particularly crucial for patients receiving anticoagulants or thrombolytic agents, as delayed re-bleeding can occur hours after the procedure.

Complications

The radial artery blood gas sampling procedure, although relatively safe, is associated with several potential complications. These complications and their preventive measures are detailed below [16]:

  1. Arteriospasm and Temporary Arterial Occlusion
    Arteriospasm can lead to temporary arterial occlusion, which may compromise blood flow to the affected limb. This can be prevented by helping the patient relax through clear explanations of the procedure, ensuring the patient is in a comfortable position, and using analgesia when necessary.

  2. Excessive Bleeding or Hematoma Formation
    Excessive bleeding or hematoma may cause compartment syndrome and subsequent limb ischemia. Prevention involves avoiding puncturing the far side of the artery, applying immediate and firm pressure at the puncture site for at least 3–5 minutes in non-anticoagulated patients, or 10–15 minutes for those on anticoagulants or with coagulopathy. Close monitoring is essential to ensure cessation of bleeding.

  3. Nerve Damage
    Nerve damage may occur during the procedure and can present as persistent pain or paresis. To minimize this risk, healthcare personnel should select an appropriate sampling site and avoid excessive redirection of the needle during the procedure.

  4. Vasovagal Response or Fainting Episodes
    A vasovagal response may lead to fainting or lightheadedness in some patients. This can be mitigated by ensuring the patient is in a supine position with their feet elevated.

  5. Infection at the Puncture Site or Needle-Stick Injuries
    Infection at the puncture site and needle-stick injuries pose risks to both patients and healthcare personnel. Strict adherence to infection prevention and control measures, such as using aseptic techniques and wearing appropriate personal protective equipment, is essential to prevent these complications.

  6. Air or Thrombus Embolism
    Air or thrombus embolism may occur if air bubbles are introduced during sampling or if an inappropriate syringe is used. This risk can be reduced by expelling air bubbles from the syringe and using a properly heparinized syringe during the procedure.

  7. Anaphylaxis from Local Anesthetic Agents
    Anaphylaxis may occur in response to local anesthetic agents. Taking a thorough patient history regarding previous allergic reactions or anaphylaxis is crucial before administering local anesthesia.

  8. Specific Concerns for Femoral Sampling
    In cases involving femoral artery sampling, be particularly cautious about bleeding complications. The larger caliber and deeper location of the femoral artery can allow significant blood accumulation without immediate clinical findings, increasing the risk of circulatory compromise.

  9. Other Notable Complications

    • Local Pain: May occur at the puncture site but can be minimized with proper technique and patient reassurance.
    • Vessel Laceration: Can result in profuse bleeding, requiring immediate evaluation and management.
    • Compartment Syndrome: A rapidly expanding hematoma may compromise regional circulation, necessitating prompt intervention. Symptoms include pain, paresthesias, pallor, absence of pulses, and persistent limb pain.
    • Limb Ischemia: Caused by arterial occlusion, thrombus formation, or vasospasm, it may present as absent distal pulses, coldness, and skin discoloration.

Hints and Pitfalls

To optimize the accuracy and success of radial ABG sampling while minimizing patient discomfort and complications, the following considerations should be observed [20]:

  1. Analgesia for Patient Comfort
    For patients experiencing anxiety or pain during the procedure, cryoanalgesia can be applied by placing an ice bag on the wrist for 3 minutes before arterial puncture. Alternatively, 0.5–1 mL of lignocaine 1% can be injected superficially to create a small wheal at the puncture site 30–60 seconds prior to sampling. Care should be taken to avoid deeper or larger volume injections, which may distort the anatomy and hinder vessel identification.

  2. Preventing Pre-Analytic Errors
    ABG measurements are highly sensitive to pre-analytic errors, including:

    • Presence of air in the sample, which can falsely elevate PaO2 and lower PaCO2.
    • Collection of venous rather than arterial blood.
    • Clotted samples due to improper anticoagulation, inadequate mixing, or exposure to air.
    • Delays in sample analysis exceeding 15 minutes at room temperature or 60 minutes at 4°C.

  3. Cooling Samples to Preserve Accuracy
    If analysis is expected to be delayed beyond 15 minutes, samples should be stored in a container with crushed ice to reduce metabolic activity of leukocytes and platelets. This prevents oxygen consumption and the associated clinically significant fall in PaO2, particularly in patients with leukocytosis or thrombocytosis.

  4. Impact of Air Bubbles
    Air bubbles introduced into the sample equilibrate with arterial blood, artificially increasing PaO2 toward 150 mmHg and decreasing PaCO2 toward 0 mmHg. Careful handling is essential to avoid air contamination.

  5. Use of Heparin as an Anticoagulant
    Heparin must be added to the syringe to prevent clotting. Flushing the syringe with heparin leaves an adequate amount in the dead space to ensure anticoagulation without affecting ABG results. Excess heparin should be expelled, as it can alter pH (falsely low) and gas measurements (falsely low PaO2 and PaCO2).

  6. Frequency of Sampling and Site Rotation
    The frequency of ABG sampling should be dictated by the patient’s clinical status. Repeated sampling at the same site increases the risk of hematoma, scarring, and arterial damage. Alternative sites should be used, or an indwelling catheter may be considered for patients requiring frequent sampling.

  7. Techniques for Unsuccessful Sampling
    Avoid pulling back the syringe plunger during unsuccessful attempts, as this increases the likelihood of venous sampling. Instead, withdraw the needle slowly until it is just beneath the skin and reattempt. Successful arterial sampling is indicated by the passive filling of the syringe with bright red, pulsating blood.

Special Patient Groups

Performing ABG sampling in pediatric patients presents unique challenges due to their fear, anxiety, and anticipation of pain, which may result in uncooperative behavior [20]. It is crucial to explain the procedure thoroughly to both the child and their parents before starting, ensuring informed consent is obtained. Allowing parents to be present during the procedure can provide comfort to the child, but healthcare providers should be mindful of the possibility that the parent may faint. In some cases, physical restraint of the child may be necessary to complete the procedure, although this approach could potentially traumatize the child. An alternative to percutaneous arterial sampling is capillary blood sampling from the heel, which can be used for gas analysis when arterial access is unavailable or when the clinician is less confident performing an arterial puncture.

For infants, arterial blood can be obtained from the radial, brachial, or dorsalis pedis arteries, while the umbilical arteries are an option in newborns. The radial artery remains the site of choice. In these patients, a small-gauge butterfly needle is preferred over the standard needle and syringe used in adults. Unlike adults, continuous but gentle suction should be applied during the procedure, and the appearance of pulsating blood is a reassuring sign that the radial artery has been successfully punctured.

In obese, edematous, or pregnant patients, the anatomical landmarks for arterial puncture may be difficult to identify. In such cases, the use of ultrasound guidance is highly beneficial for locating the artery. Ultrasound not only improves the success rate of arterial access but also reduces potential complications associated with repeated punctures, such as injury to the vessel or surrounding tissues.

Both pediatric and pregnant populations require special attention due to their unique anatomical and physiological considerations. In pediatrics, fear and discomfort associated with the procedure can make the hospital experience traumatic, emphasizing the need for proper explanation, comfort measures, and, when appropriate, pain-reducing products. In pregnant patients, the challenges often stem from anatomical changes caused by fluid retention or increased body mass.

Authors

Picture of Gan Kiat Kee

Gan Kiat Kee

Dr Gan Kiat Kee is an enthusiastic and passionate emergency physician from Hospital Sultanah Aminah Johor Bahru, Johor, Malaysia. He has obtained his medical degree from University Sains Malaysia and completed his post-graduate training in emergency medicine from the same university. He has special interest in acute trauma care and ultrasound guided procedures especially in ultrasound guided regional anaesthesia for pain management in trauma patient. He is also the founder for Emergency Department Regional Anaesthesia (EDRA) of his current working department. Owing to his great interest in simulation and bedside teaching, he has been appointed as adjunct lecturer by Clinical School Johor Bahru, Monash University Malaysia and has been active in teaching various life support.

Picture of Arif Alper Cevik, MD, FEMAT, FIFEM

Arif Alper Cevik, MD, FEMAT, FIFEM

Prof Cevik is an Emergency Medicine academician at United Arab Emirates University, interested in international emergency medicine, emergency medicine education, medical education, point of care ultrasound and trauma. He is the founder and director of the International Emergency Medicine Education Project – iem-student.org, chair of the International Federation for Emergency Medicine (IFEM) core curriculum and education committee and board member of the Asian Society for Emergency Medicine and Emirati Board of Emergency Medicine.

Listen to the chapter

References

  1. Hassan W, Martinez S. Arterial Blood Gas Sampling [ABG Machine Use]. In: StatPearls. Treasure Island, FL: StatPearls Publishing; 2024. Updated May 9, 2024. Accessed January 1, 2025. https://www.ncbi.nlm.nih.gov/books/NBK606112/
  2. Danckers M. Arterial blood sampling for arterial blood gas analysis. Medscape. Updated February 29, 2024. Accessed January 1, 2025. https://emedicine.medscape.com/article/1902703-overview
  3. Castro D, Patil SM, Zubair M, Keenaghan M. Arterial Blood Gas. In: StatPearls. Treasure Island, FL: StatPearls Publishing; 2024. Updated January 8, 2024.
  4. Kitamura BC, Sarko J. Arterial Blood Gas. In: Sherman SC, Weber JM, Schindlbeck MA, et al., eds. Clinical Emergency Medicine. New York, NY: McGraw-Hill Education; 2014. Accessed January 1, 2025. https://accessemergencymedicine.mhmedical.com/content.aspx?bookid=991&sectionid=57306093
  5. Rowe BH, Bhutani M, Stickland MK, Cydulka R. Assessment and management of chronic obstructive pulmonary disease in the emergency department and beyond. Expert Rev Respir Med. 2011;5(4):549-559.
  6. Arena A, Miller E. Respiratory acid-base disorders. Emerg Med Clin North Am. 2023;41(4):863-875. doi:10.1016/j.emc.2023.06.009
  7. Rose JJ, Wang L, Xu Q, et al. Carbon monoxide poisoning: pathogenesis, management, and future directions of therapy. Am J Respir Crit Care Med. 2017;195(5):596-606. doi:10.1164/rccm.201606-1275CI
  8. American Association for Respiratory Care. AARC clinical practice guideline: sampling for arterial blood gas analysis. Respir Care. 1992;37(8):891-897.
  9. Theodore AC. Venous blood gases and other alternatives to arterial blood gases. In: Manaker S, Finlay G, eds. UpToDate. Waltham, MA: UpToDate; 2021. Accessed February 2, 2021. https://www.uptodate.com/contents/venous-blood-gases-and-other-alternatives-to-arterial-blood-gases
  10. Dev SP, Hillmer MD, Ferri M. Arterial puncture for blood gas analysis. N Engl J Med. 2011;364(5):e7.
  11. Liang SY, Theodoro DL, Schuur JD, Marschall J. Infection prevention in the emergency department. Ann Emerg Med. 2014;64(3):299-313. doi:10.1016/j.annemergmed.2014.02.024
  12. Gerhard-Herman MD, Gornik HL, Barrett C, et al. 2016 AHA/ACC guideline on the management of patients with lower extremity peripheral artery disease: executive summary. Circulation. 2017;135(12):e686-e725. doi:10.1161/CIR.0000000000000470
  13. Sony S, Shekhar S, Walikar BN, Shiwali S. Raynaud’s phenomenon during non-operating room anesthesia: a case report. Cureus. 2022;14(12):e32906. doi:10.7759/cureus.32906
  14. Satiani B, Sowden DT. Hand ischemia. J Fam Pract. 1982;15(1):163-169.
  15. Rowling SC, Fløjstrup M, Henriksen DP, et al. Arterial blood gas analysis: as safe as we think? A multicentre historical cohort study. ERJ Open Res. 2022;8(1):00535-2021. doi:10.1183/23120541.00535-2021
  16. Danckers M, Fried ED. Arterial blood sampling for arterial blood gas analysis. Medscape. Updated February 29, 2024. Accessed January 4, 2025. https://emedicine.medscape.com/article/1902703-overview
  17. World Health Organization. WHO guidelines on drawing blood: best practices in phlebotomy. Geneva: World Health Organization; 2010. Accessed January 4, 2025. https://www.ncbi.nlm.nih.gov/books/NBK138661/
  18. Lightowler JV, Elliott MW. Local anaesthetic infiltration prior to arterial puncture for blood gas analysis: a survey of current practice and a randomised double blind placebo controlled trial. J R Coll Physicians Lond. 1997;31(6):645-648.
  19. Pagnucci N, Pagliaro S, Maccheroni C, et al. Reducing pain during emergency arterial sampling using three anesthetic methods: a randomized controlled clinical trial. J Emerg Med. 2020;58(6):857-864.
  20. Ambroz M, Prosen G. Arterial blood gas (ABG) sampling. International Emergency Medicine Education Project. Accessed January 4, 2025. https://iem-student.org/arterial-blood-gas-abg-sampling/

Reviewed and Edited By

Picture of Arif Alper Cevik, MD, FEMAT, FIFEM

Arif Alper Cevik, MD, FEMAT, FIFEM

Prof Cevik is an Emergency Medicine academician at United Arab Emirates University, interested in international emergency medicine, emergency medicine education, medical education, point of care ultrasound and trauma. He is the founder and director of the International Emergency Medicine Education Project – iem-student.org, chair of the International Federation for Emergency Medicine (IFEM) core curriculum and education committee and board member of the Asian Society for Emergency Medicine and Emirati Board of Emergency Medicine.

Airway Procedures (2024)

~ iEM Education Project Team ~ Leave a comment

by Eirini Trachanatzi & Anastasia Spartinou

Authors
Listen

Introduction

Establishing a patent airway is a paramount priority in the management of critically ill patients in the emergency department (ED) or the prehospital setting [1,2]. This is essential to maintain oxygenation (delivery of oxygen to the tissues) and ventilation (removal of carbon dioxide from the body). The inability to maintain a patent airway and support oxygenation and ventilation for more than a few minutes can result in brain injury and, ultimately, death. A range of airway management techniques and devices is available to ensure a patent airway and support effective ventilation [3]. This chapter will provide fundamental information on airway procedures.

Basic Airway Opening Maneuvers

Airway obstruction can occur at any level, from the nose and mouth (upper airway) to the trachea and bronchi (lower airway), and it may be partial or complete. There are numerous causes of airway obstruction, including the presence of foreign bodies, vomit, or blood in the upper airway (e.g., regurgitation of gastric contents or trauma) [4]. Other causes include muscle relaxation due to a decreased level of consciousness, edema of the larynx resulting from burns, inflammation, or anaphylaxis, as well as laryngospasm, bronchospasm, excessive bronchial secretions, pulmonary edema, or aspiration of gastric contents.

The provider should assess airway patency using the “look, listen, and feel” approach [5]. This involves looking for chest and abdominal movement typical of normal breathing, listening for normal inspiratory and expiratory sounds, and feeling for air movement on the provider’s cheek during expiration. Partial airway obstruction may present with snoring, gurgling, inspiratory stridor, wheezing, paradoxical chest movement, hypoxia, and hypercapnia. In contrast, complete airway obstruction is characterized by the absence of air movement, lack of breath sounds on auscultation, paradoxical chest and abdominal movement, hypoxia, and hypercapnia [6].

Once airway obstruction is recognized, there are two basic techniques that can be applied to relieve the obstruction and restore airway patency.

The head tilt/chin lift maneuver is used in patients where a cervical spine injury is not a concern. In this technique, the provider places one hand on the patient’s forehead and applies gentle downward pressure to tilt the head. Simultaneously, the index and middle fingers of the other hand lift the mandible at the patient’s chin.

Image 1 - head tilt - chin lift manoeuvre

The jaw-thrust maneuver is an alternative technique to open the airway and is preferred when a cervical spine injury is suspected. The first step involves locating the angle of the mandible. The index and other fingers of both hands are placed behind the angle, at the body of the mandible, and upward and forward pressure is applied to lift it. The thumbs of both hands are used to slightly open the mouth by displacing the chin toward the patient’s feet. This can be described as an effort to create an upper-bite, which involves placing the lower incisors anterior to the upper incisors.

Image 2 - jaw thrust manoeuvre 1
Image 3 - jaw thrust manoeuvre 2

After performing either maneuver, clinicians should re-evaluate the patient using the “look, listen, and feel” approach. Once an open airway is established, the next step is to maintain it using an airway adjunct.

Application Of Airway Adjuncts

Introduction
Oropharyngeal (OPA) and nasopharyngeal (NPA) airways are useful adjuncts for maintaining an open airway. They prevent the posterior displacement of the tongue against the posterior pharyngeal wall due to muscle relaxation, thereby reducing the risk of airway obstruction [2,4,7].

Indications
OPA and NPA are used to maintain a patent airway. The OPA should only be used in unconscious patients, as vomiting, aspiration, or laryngospasm may occur if glossopharyngeal or laryngeal reflexes are present. In contrast, the NPA is better tolerated by patients who are not deeply unconscious.

Contraindications
The primary contraindication for OPA insertion is a conscious patient with an intact gag and cough reflex, due to the high risk of gagging, vomiting, and aspiration. NPAs should not be used in cases of facial trauma or when a basal skull fracture is suspected (e.g., raccoon eyes or battle sign). Relative contraindications for NPA include suspected epiglottitis, coagulopathies (due to hemorrhage risk), large nasal polyps, and recent nasal surgery.

Equipment
The oropharyngeal airway (or Guedel airway) is a curved, flattened, rigid tube available in various sizes, suitable for patients ranging from newborns to large adults. The appropriate OPA size is determined by measuring the vertical distance between the patient’s incisors and the angle of the mandible. Typical adult sizes are 3, 4, and 5.

Image 4 - Oropharyngeal Airways (OPAs)

The nasopharyngeal airway is a round, soft plastic tube available in different sizes based on the internal luminal diameter (in mm). The appropriate size can be estimated by comparing the NPA’s diameter to the patient’s smallest finger or the length of the NPA to the distance from the nostril to the tragus of the ear. Typical adult sizes are 6 mm, 7 mm, 8 mm, and 9 mm.

Image 5 - Nasopharyngeal Airways (NPAs)

Procedure Steps

  1. Insertion of an Oropharyngeal Airway:

    • Open the patient’s mouth and ensure no foreign materials could be pushed into the larynx during insertion.
    • There are two methods for OPA insertion. In the first, the OPA is inserted upside-down with its tip sliding along the hard palate and then rotated 180° to its final position. This method is typically used for adults.
    • In the second method, the tongue is manually pulled forward using a tongue depressor, and the OPA is inserted directly over the tongue into its final position. This method is preferred for children.

  2. Insertion of a Nasopharyngeal Airway:

    • Choose the larger nostril (typically the right) for insertion. Topical anesthetic spray may be applied.
    • Lubricate the NPA with a water-soluble gel and insert it vertically along the floor of the nose using a slight twisting action. The curve of the airway should be directed towards the patient’s feet.
    • If resistance is encountered, never force the NPA. Instead, remove it and attempt insertion through the other nostril.

Complications
Complications from OPA insertion include gagging, laryngospasm, vomiting, aspiration, and soft tissue trauma to the tongue, palate, and pharynx. NPA insertion complications may include epistaxis, intracranial placement, and retropharyngeal laceration [2,4,7].

Bag-Valve Mask Ventilation

Introduction
Bag-valve mask ventilation (BMV) is an essential skill for every emergency provider. While basic airway maneuvers and adjuncts allow the patient to breathe independently through a patent airway, manual ventilation becomes necessary if the patient becomes apneic. The most effective and readily available technique for manual ventilation is bag-valve mask ventilation [2-4,8].

Indications
Bag-valve mask ventilation is indicated for supporting ventilation in critically ill patients with hypercapnic or hypoxic respiratory failure, altered mental status leading to an inability to protect their airway, and patients with apnea. Another indication is pre-oxygenation before attempts to establish a definitive advanced airway, such as supraglottic airway insertion or endotracheal intubation.

Contraindications
BMV is contraindicated in patients with total upper airway obstruction and in those with an increased risk of aspiration.

Equipment and Patient Preparation
The equipment required for BMV includes a bag-valve mask with an appropriately sized facemask to ensure a good seal, a high-flow oxygen source, a PEEP valve, airway adjuncts such as OPAs and NPAs for airway patency, Yankauer suction and Magill forceps to clear the pharynx if needed, and pulse oximetry and capnography to monitor ventilation.

The bag-valve mask consists of:

  • A self-inflating resuscitation device (a plastic bag that re-expands after being squeezed), available in sizes such as 250 ml, 500 ml, and 1500 ml for infants, children, and adults, respectively.
  • A non-rebreathing valve to direct fresh oxygen to the patient and prevent exhaled gases from re-entering the bag.
  • A PEEP valve (optional) attached to the exhalation port.
  • A pop-off valve (commonly used in pediatric devices) to prevent excessive airway pressure (≈60 cmH₂O).
  • An oxygen inlet and air intake valve.
  • An oxygen reservoir bag with one-way valves.

Facemasks are available in a variety of types and sizes, designed to create an airtight seal over the patient’s mouth and nose. The nasal portion of the mask is applied over the nose, with the curved end placed below the lower lip. Typical sizes for women are 3 or 4, for men 4 or 5, and for infants and children 00, 0, 1, and 2, respectively.

Image 6 - bag mask with explanation

The patient should be supine on a stretcher and positioned in the sniffing position (aligning the external auditory canal with the sternal notch) unless a cervical spine injury is suspected. The provider is positioned at the head of the patient. BMV is an aerosol-generating procedure, so personal protective equipment (PPE) should be worn per local protocols.

Procedure Steps [2-4,8]

  1. One-Person Technique
    In the one-person technique, the provider uses the “E-C seal.” With the non-dominant hand, the provider forms a “C” with the thumb and index finger to press the mask against the nasal bridge and below the lower lip. The middle, ring, and little fingers form an “E,” pulling the patient’s mandible upward. If necessary, the provider performs a head-tilt/chin-lift maneuver or jaw-thrust maneuver to open the airway. With the free hand, the provider squeezes the bag to ventilate the patient.

  2. Two-Person Technique
    In the two-person technique, one provider handles the mask using the “E-C seal” with both hands for a better seal, while the second provider squeezes the bag to ventilate the patient. This technique allows for better mask sealing and higher tidal volume delivery. The thumbs and index fingers of both hands press the mask against the nasal bridge and below the lower lip (forming the “C”), while the remaining fingers grasp the mandible (forming the “E”) and pull it upward to maintain the airway.

  3. Ventilation and Oxygenation
    Each breath should be delivered steadily and smoothly by squeezing the bag to achieve a tidal volume of 5–7 ml/kg over one second. The bag is then released to allow re-inflation. Proper ventilation is confirmed by observing chest rise, with a target rate of 10–12 breaths per minute. Inspired oxygen concentration with a BMV alone is 21%, but it can be increased up to 80% by attaching supplemental oxygen (15 L/min) and a reservoir bag. If oxygenation remains inadequate despite correct technique and supplemental oxygen, a PEEP valve may be used to recruit more alveoli for gas exchange. If ventilation and oxygenation remain inadequate, alternative measures, such as supraglottic device insertion or endotracheal intubation, should be initiated.

Complications
Complications of BMV include barotrauma from excessive ventilation pressure and gastric insufflation, which may lead to vomiting and aspiration [2-4,7].

Supraglottic Airway Devices (SGA)

Introduction
Supraglottic airway devices (SGAs) are inserted blindly into the patient’s oropharynx, positioned above the glottis, allowing for ventilation and oxygenation over a short period. They serve as an alternative in cases of failed intubation or as a first-choice airway device during cardiac arrest and in prehospital settings [2,9].

Indications
The primary indications for SGA insertion include:

  • Acting as a rescue device in cases of difficult or failed intubation attempts.
  • Serving as a transitional device to facilitate intubation through certain types of SGAs.
  • Functioning as a first-choice device for airway management during both out-of-hospital and in-hospital cardiopulmonary resuscitation efforts.

Contraindications
SGA insertion is contraindicated in the following cases:

  • Inability to adequately open the patient’s mouth.
  • Total airway obstruction.
  • Increased risk of aspiration of gastric contents.
  • Requirement for high inspiratory pressures.

Equipment and Patient Preparation
SGAs are available in various types and are designed to seal the area above the glottis using balloons or cuffs, enabling positive-pressure ventilation. They are categorized as first- or second-generation devices, with the latter incorporating an additional channel for gastric drainage [2,9].

  • Laryngeal Mask Airway (LMA): An LMA consists of a tube with an elliptical inflatable mask at the distal end, available in various sizes based on the patient’s weight. Common models include:

    • Classic™ LMA: A reusable or disposable first-generation LMA.
    • Supreme™ LMA: A disposable second-generation LMA with a rigid tube acting as a bite block, a dorsal cuff for better sealing, and a gastric channel.
    • Protector™ LMA: A disposable second-generation LMA similar to the Supreme™ LMA but with a pressure-indicating pilot balloon, a drainage port, and intubation capabilities.
    • Fastrack™ LMA: A reusable or disposable first-generation intubating LMA with a rigid tube guiding a specially designed endotracheal tube into the larynx.
Image 7 - classic laryngeal mask airway (LMA)
Image 8 - protector LMA
  • i-gel®: A second-generation SGA featuring a gel-like, non-inflatable distal end made of thermoplastic elastomer, a bite block, and a gastric channel. Sizes are determined by the patient’s weight.
Image 9 - igel

  • Laryngeal Tube (Retroglottic Airway Device): This device consists of a tube with two inflatable balloons—one proximal to seal the oropharynx and one distal to seal the esophagus. Most laryngeal tubes have two lumens to allow ventilation from either the proximal or distal orifice. Sizes are based on patient height or weight.

Procedure Steps

  1. Preparation: Select the appropriate SGA size based on the patient’s physical characteristics. Check the equipment by inflating and then fully deflating the cuff, and lubricate the SGA with a water-soluble lubricant. Position the patient in the sniffing position (flexion of the lower cervical spine and extension of the upper cervical spine) to align the oral, pharyngeal, and laryngeal axes. Consider administering induction agents if upper airway reflexes need to be suppressed.
  2. Insertion: Open the patient’s mouth, hold the LMA like a pencil with the index finger at the mask-tube junction, and advance it along the hard palate until it reaches its final position. Inflate the cuff as indicated on the device packaging. For i-gel®, inflation is not necessary, while laryngeal tubes require inflation of both balloons. Secure the device once in place.

Complications
While ventilation success rates with SGAs are high, complications may occur, including [2,9]:

  • Aspiration of gastric contents.
  • Inability to ventilate due to inappropriate size or misplaced device.
  • Laryngospasm if upper airway reflexes are intact.
  • Local edema from excessive pressure on adjacent structures.

Hints and Pitfalls

  • In a fully deflated LMA, the mask tip may flip or roll, leading to non-optimal placement. Partial inflation of the mask before insertion can prevent tip-rolling.
  • Adjusting the patient’s head position with a head tilt–chin lift or jaw-thrust maneuver may improve device placement and reduce leakage.

Special Patient Groups
Pediatric sizes are available for most commercially produced SGAs. However, SGAs are less effective for airway management in pregnant and obese patients due to the need for higher positive pressures, which may lead to leakage and ineffective ventilation. Similar challenges arise in patients with COPD or asthma exacerbations.

Endotracheal Intubation

Introduction
Endotracheal intubation involves placing an airtight-sealed tube into the patient’s trachea to ensure airway patency for ventilation and to protect against aspiration. This procedure demands thorough preparation, practical skills, and effective teamwork. Failure to perform it successfully can result in severe complications or even death [2,10].

Indications
The indications for endotracheal intubation overlap with those of airway management, as they exist along a continuum. They can be categorized into three main groups:

  1. Inability to maintain a patent airway and risk of aspiration (e.g., acutely decreased mental status or impending airway obstruction).
  2. Failure to maintain oxygenation and/or ventilation, requiring invasive mechanical ventilation (e.g., severe exacerbations of asthma or COPD).
  3. Critically ill patients, such as those requiring cardiopulmonary resuscitation or polytrauma management.

Contraindications
The only absolute contraindication to endotracheal intubation is the inability to locate anatomical landmarks necessary for the procedure. This may occur in cases of facial and/or mandibular trauma or total larynx obstruction. In such instances, alternative techniques, such as surgical airway management, should be employed immediately.

Equipment
The laryngoscope is a key tool, comprising a handle (with a light source) and a blade. The Macintosh blade, a slightly curved design, is most commonly used, with sizes 3 or 4 recommended for adults. Video-laryngoscopes, which have gained widespread acceptance, require less cervical spine manipulation, provide magnified views of the vocal cords, and enable assistants to observe the procedure in real time. Video-laryngoscopes come with different blade types (e.g., Macintosh or hyper-angulated blades).

Image 10 - laryngoscope with Macintosh blade
Image 11 - videolaryngoscope 1
Image 12 - videolaryngoscope 2

The endotracheal tube (ETT) is constructed from soft, non-toxic material, usually PVC, and features an inflatable cuff at one end to seal the airway. The size of the tube is determined by its internal diameter (e.g., 8.0–8.5 mm for adult males and 7.0–7.5 mm for adult females).

Image 13 - Endotracheal Tube (ETT)

Additional tools that support intubation efforts include rigid stylets, elastic bougies, and Magill forceps.

Procedure Steps

Airway management in emergency settings typically follows the principles of Rapid Sequence Induction (RSI), which involves administering an induction agent and a neuromuscular blocking agent to facilitate ETT placement without bag-mask ventilation, minimizing aspiration risk. Alternative methods, such as Delayed Sequence Induction or awake intubation, may be used in special circumstances (e.g., anatomical or physiological difficulties) [11].

RSI follows a seven-step process known as the “7 Ps”:

(1) Preparation

  • Proper preparation is key to a successful, uneventful procedure. Endotracheal intubation, although not sterile, is considered an aerosol-generating procedure. Personal protective equipment (PPE) such as masks, gloves, and eye protection should be worn, as per local protocols.
  • Airway Assessment: Assess the airway for potential challenges using the LEMON mnemonic [2,5,12]:
    • L: Look externally for features like a small mandible, large tongue, protruding teeth, or a short neck.
    • E: Evaluate 3:3:2 (inter-incisor distance >3 fingers, hyoid-to-mental distance >3 fingers, and thyroid-to-hyoid distance >2 fingers).
    • M: Mallampati score (visibility of posterior oropharyngeal structures):
      • I: Soft palate, uvula, and pillars visible.
      • II: Soft palate and uvula visible.
      • III: Soft palate and base of the uvula visible.
      • IV: Only the hard palate visible.
    • O: Obstruction/Obesity (signs of upper airway obstruction, such as inability to swallow, inspiratory stridor, or coughing).
    • N: Neck mobility (e.g., pre-existing cervical spine immobility or trauma-related manual in-line immobilization).

    • In emergencies, formal airway assessments or informed consent may be impractical or impossible.

iEM-infographic-pearls-airway - Assessing Airway Difficulty

  • Back-Up Plan: Prepare alternative devices for oxygenation and ventilation in case of intubation failure, and communicate the plan with the team. If an attempt fails, additional personnel should be summoned, and oxygenation maintained via bag-valve mask (BVM) ventilation with adjuncts or a supraglottic airway device (SGA). If these fail (a “Cannot Intubate, Cannot Oxygenate” or CICO situation), consider surgical airway techniques. Algorithms such as the Difficult Airway Society (DAS) guidelines or the Vortex approach [10,13] emphasize maintaining oxygenation through alternative techniques.

  • Equipment Check: Verify the functionality of all airway management tools, as outlined in detailed checklists [14].

Monitoring (ECG, BP, SpO2, EtCO2)

Laryngoscope (DL or VL)

Vascular access

ET tube (various sizes)

Oxygen source

Syringe (ET cuff inflation)

Suction device (Yankauer)

Stylets (various sizes)

Bag-mask ventilation device

Gum elastic Bougie

Oropharyngeal and Nasopharyngeal airways (various sizes)

ETT stabilization device

Medications (drawn up and labeled)

Rescue devices (supraglottic devices, surgical airway kit)

(2) Pre-Oxygenation

The administration of a neuromuscular blocking agent leads to the cessation of automatic breathing within seconds. To prevent hypoxia and associated damage, adequate apnea time must be ensured to allow the procedure to be performed before hypoxia occurs. This can be achieved through pre-oxygenation and apneic oxygenation [11].

Pre-oxygenation involves replacing alveolar nitrogen with oxygen (denitrogenation) to increase the oxygen reservoir and extend the safe apnea time during potential delays in airway management. Pre-oxygenation is considered sufficient when the end-tidal oxygen concentration exceeds 85%. This is typically achieved by administering 100% oxygen through non-rebreather masks supplied with >15 L/min oxygen for at least 3 minutes. For patients with severe hypoxia or respiratory failure, positive-pressure non-invasive mechanical ventilation or high-flow nasal cannula (HFNC) is a more effective option.

Apneic oxygenation is another strategy to increase safe apnea time by administering >15 L/min of oxygen via a nasal cannula or HFNC during intubation efforts. This method achieves an oxygen pressure gradient even during apnea.

Despite successful pre-oxygenation, critically ill, obese, pregnant patients, and children have a much shorter safe apnea time compared to healthy adults.

(3) Pre-Intubation Optimization (First Resuscitate – Then Intubate)

While anatomical difficulty may be present in a few patients, most emergency intubations involve patients with physiological challenges [12,15]. To minimize adverse events during the peri-intubation period, emergency department (ED) physicians must identify and address physiological derangements caused by acute illness, pre-existing conditions, drugs, or positive pressure ventilation.

Key considerations for optimization include:

  • Hypoxemia: Consider pre-oxygenation, positive pressure ventilation, apneic oxygenation, or chest-tube insertion in cases of pneumothorax.
  • Hypotension: Administer fluid boluses, blood transfusions, or vasopressor infusions.
  • Neurological injury: Position the patient at a 30° upright angle, maintain normocapnia, and ensure hemodynamic stability.

(4) Paralysis with induction

Pre-treatment agents can be utilized to mitigate the sympathetic response triggered by laryngoscopy. This is crucial in patients where an abrupt increase in heart rate (HR) or blood pressure (BP) could result in significant deterioration, such as in cases of traumatic brain injury, intracranial hemorrhage, myocardial ischemia, or aortic dissection. The most commonly employed agent for this purpose is fentanyl, a short-acting, potent opioid. Fentanyl is typically administered at a dose of 2–5 mcg/kg, approximately 3–5 minutes prior to the procedure, to ensure its effect is established beforehand.

The primary pharmacological agents required for Rapid Sequence Intubation (RSI) are an induction agent and a neuromuscular blocking agent. Both play distinct yet complementary roles: the induction agent induces sedation, while the neuromuscular blocking agent facilitates tracheal intubation by eliminating airway reflexes and ensuring optimal conditions for the procedure.

There is no single agent of choice. The most commonly used induction agents for Rapid Sequence Intubation (RSI) are as follows [11]:

  • Ketamine: As an NMDA receptor antagonist, ketamine provides analgesia, sedation, and amnesia while preserving the respiratory drive. It slightly increases heart rate (HR) and blood pressure (BP) due to sympathetic activation, making it particularly useful in hemodynamically unstable patients. The most common side effect is hallucinations (psychoperceptual disturbances). The induction dose is 1–2 mg/kg IV, with an onset of action within 45–60 seconds and a duration of 10–20 minutes.

  • Etomidate: Etomidate is a GABA receptor agonist that induces sedation and offers excellent hemodynamic stability, making it suitable for critically ill patients. It may cause transient myoclonic movements during induction. Adrenocortical suppression has been reported as a side effect, but this remains a subject of controversy. The induction dose is 0.2–0.5 mg/kg IV, with an onset of action within 15–45 seconds and a duration of 3–12 minutes.

  • Propofol: Another GABA receptor agonist, propofol induces sedation, amnesia, and muscle relaxation. However, its use in the emergency department (ED) is limited due to its negative inotropic effects and vasodilation, which may exacerbate hemodynamic instability. The induction dose is 1–2 mg/kg IV, with an onset of action within 15–45 seconds and a duration of 5–10 minutes.

  • Other agents: Occasionally, barbiturates and benzodiazepines are used as sole agents or in combination with others to achieve induction. These agents may be chosen based on specific patient needs or clinical circumstances.

Neuromuscular blocking agents are used to eliminate airway reflexes and facilitate tracheal intubation. Rapid Sequence Intubation (RSI) requires rapid-acting agents, and the most commonly used agents are as follows:

  • Rocuronium: Rocuronium is a non-depolarizing neuromuscular blocking agent with a rapid onset and intermediate duration of action. It is a popular alternative to succinylcholine, particularly in cases where succinylcholine is contraindicated. Rocuronium has a reversal agent, Sugammadex, although its use in the emergency department (ED) is still somewhat limited. The induction dose is 1–1.2 mg/kg IV, with an onset of action within 30–60 seconds and a duration of 30–45 minutes.

  • Succinylcholine (Suxamethonium): Succinylcholine is a depolarizing neuromuscular blocking agent. Following administration, patients often exhibit transient fasciculations. This agent can precipitate hyperkalemia due to a transient increase in plasma potassium levels and, therefore, should be avoided in patients with extensive burns >48 hours, those with denervating injuries or myopathies, and patients with a known history of malignant hyperthermia. The induction dose is 1.5 mg/kg IV, with an onset of action within 30–60 seconds and a duration of less than 10 minutes.

(5) Positioning

Optimal positioning of the patient will improve upper airway patency and access, increase functional residual capacity, and reduce the risk of aspiration. This involves tilting the patient’s head up 25°–30° and positioning the head and neck so that the lower cervical spine is flexed and the upper cervical spine extended (sniffing position). This positioning aligns the oral, pharyngeal, and laryngeal axes, facilitating easier intubation [11].

In cases of trauma, manual-in-line stabilization (MILS) should be employed to protect the cervical spine from further damage during airway management procedures. Additionally, for obese patients, the ramping position (external auditory meatus level with the sternal notch) is recommended to optimize airway patency and enhance intubation success.

(6) Placement with Proof

Laryngoscopy is the procedure that allows direct (or indirect, in the case of video-laryngoscopy) visualization of the vocal cords to facilitate the insertion of the Endotracheal Tube (ETT) through them into the patient’s trachea [11].

  1. Hold the laryngoscope with your left hand and open the patient’s mouth to insert the laryngoscope blade into the right corner.
  2. Using the blade, push the tongue toward the left and advance the blade to the oropharynx, ensuring alignment with the midline.
  3. Visualize the epiglottis and lift it to reveal the vocal cords.
  4. Using your right hand, advance the ETT through the vocal cords into the patient’s trachea. Ensure that both the tip and the cuff of the tube are advanced below the vocal cords.
  5. Inflate the tube’s cuff to achieve an airtight seal of the airway.
  6. Confirm the ETT’s placement with the use of capnography.
  7. Auscultate to verify that the tube ventilates both lungs.
  8. Secure the ETT.

(7) Post-Intubation Management

Initiate ventilation either through a self-inflating bag or by connecting the patient to a ventilator. Maintain sedation through infusion or boluses. Perform a reassessment of the patient using the ABCDE approach [11].

Complications

  • Failed intubation requires prompt recognition and implementation of alternative methods of oxygenation and ventilation (rescue oxygenation through bag-mask ventilation, supraglottic airway devices, or surgical airway).
  • ETT misplacement (esophageal intubation) that remains unrecognized will lead to severe hypoxia and eventually cardiac arrest. Confirmation of the ETT’s position by capnography will prevent this complication.
  • Aspiration remains a possibility even with RSI. Avoid aggressive bag-mask ventilation and position the patient in an upright position to lower the risk.
  • Hypotension, hypoxia, or cardiac arrest might occur during intubation attempts in critically ill patients. Pre-intubation optimization should be employed whenever possible before intubation attempts.

Special Patient Groups

Pediatrics

Children have a relatively larger head and occiput, larger tongue, and small mandible, and a larynx that is more cephalad compared to adults [16]. Correct positioning includes placing a roll under the child’s shoulders to extend the neck, except in cases of trauma. Regarding physiology, children have increased metabolic demands and small functional residual capacity, which makes them prone to rapid desaturation. Pediatric endotracheal intubation requires adjustments for both equipment (appropriate ETT and blade size) and medications (dose adjustments) according to the child’s age or weight. Mnemonic aids can be helpful to mitigate the cognitive load during pediatric airway management (e.g., Broselow tape) [17].

Pregnant Patients

Pregnancy is characterized by decreased functional residual capacity, decreased gastric emptying, and airway edema. Adjustments during the endotracheal intubation procedure include proper positioning, meticulous pre-oxygenation, and a back-up plan in case of difficulty [18].

Obese Patients

Obesity severely decreases functional residual capacity, leading to rapid desaturation during airway management. Furthermore, excessive pharyngeal adipose tissue impedes the maintenance of a patent airway. Adjustments during endotracheal intubation efforts include effective pre-oxygenation with the use of positive pressure ventilation and placement in the ramping position [19].

Trauma Patients

In case of suspected cervical spine injury, manual-in-line stabilization (MILS) should be employed. Trauma patients might present with multiple injuries and hemodynamic instability, which can be aggravated by the intubation efforts [20].

In-line stabilization

Geriatrics

Airway management in the elderly presents unique challenges due to age-related physiological changes, comorbidities, and increased risk of complications. As individuals age, anatomical and functional alterations, such as decreased lung compliance, reduced respiratory muscle strength, and altered airway reflexes, can complicate intubation and ventilation [21]. Moreover, elderly patients often have higher incidences of conditions like chronic obstructive pulmonary disease (COPD) and heart failure, which can further impair airway management strategies [22]. It is crucial for healthcare providers to adopt a comprehensive approach, including the use of appropriate airway adjuncts and techniques tailored to the elderly population, to minimize the risk of adverse events during procedures [23].

Authors

Picture of Eirini Trachanatzi

Eirini Trachanatzi

My name is Eirini Trachanatzi. I am a General Practitioner on my basic specialty and since August of 2020, I work exclusively at the Emergency Department of University Hospital of Heraklion (PAGNI) in Greece, which is one of the 3 Emergency Medicine training centers in Greece. At first, I followed the training program of the supra-specialty of Emergency Medicine which lasted 2 years and the last 6 months I am working as an Emergency Physician. My special interests are the resuscitation and trauma.

Picture of Anastasia Spartinou

Anastasia Spartinou

My name is Anastasia (Natasa) Spartinou. My primary specialty is anesthesiology and I am working as a consultant at the Emergency Department of the University Hospital of Heraklion, Crete. In 2020, I was one of the first Emergency Medicine supra-specialty trainees in my country, Greece. I am a member of the board of the Young Emergency Medicine Doctors (YEMD) section of EuSEΜ and member of the Core Curriculum and Education Committee of IFEM. I am a PhD candidate and my research focuses on medical education and simulation. My special interests are medical education, resuscitation and trauma.

Listen to the chapter

References

  1. Nemeth J, Maghraby N, Kazim S. Emergency airway management: the difficult airway. Emerg Med Clin North Am. 2012;30(2):401-420. doi:10.1016/j.emc.2011.12.005.
  2. Brown CA III, Sakles JC, Mick NW, eds. The Walls Manual of Emergency Airway Management. 5th ed. Philadelphia, PA: Wolters Kluwer; 2018.
  3. Higginson R, Parry A. Emergency airway management: common ventilation techniques. Br J Nurs. 2013;22(7):366-371. doi:10.12968/bjon.2013.22.7.366.
  4. Brady MF, Burns B. Airway obstruction. In: StatPearls [Internet]. Treasure Island, FL: StatPearls Publishing; 2024 Jan–. Updated August 7, 2023. Accessed December 25, 2024. https://www.ncbi.nlm.nih.gov/books/NBK470562/
  5. Finucane BT, Tsui BC, Santora AH. Evaluation of the airway. In: Principles of Airway Management. 4th ed. New York, NY: Springer; 2010:27-58. doi:10.1007/978-0-387-09558-5_2.
  6. McPherson K, Stephens RC. Managing airway obstruction. Br J Hosp Med (Lond). 2012;73(10):C156-C160. doi:10.12968/hmed.2012.73.sup10.c156.
  7. Effective use of oropharyngeal and nasopharyngeal airways. ACLS.com. Published January 2019. Accessed December 25, 2024. https://acls.com/articles/nasopharyngeal-oropharyngeal-airways/
  8. Bosson N. Bag-valve-mask ventilation. Medscape. Updated January 29, 2024. Accessed December 25, 2024. https://emedicine.medscape.com/article/80184-overview
  9. Park HP. Supraglottic airway devices: more good than bad. Korean J Anesthesiol. 2019;72(6):525-526. doi:10.4097/kja.19417.
  10. Higgs A, McGrath BA, Goddard C, et al. Guidelines for the management of tracheal intubation in critically ill adults. Br J Anaesth. 2018;120(2):323-352. doi:10.1016/j.bja.2017.10.021.
  11. Schrader M, Urits I. Tracheal rapid sequence intubation. In: StatPearls [Internet]. Treasure Island, FL: StatPearls Publishing; 2024 Jan–. Updated October 10, 2022. Accessed December 25, 2024. https://www.ncbi.nlm.nih.gov/books/NBK560592/
  12. Kornas RL, Owyang CG, Sakles JC, Foley LJ, Mosier JM; Society for Airway Management’s Special Projects Committee. Evaluation and management of the physiologically difficult airway: consensus recommendations from Society for Airway Management. Anesth Analg. 2021;132(2):395-405. doi:10.1213/ANE.0000000000005233.
  13. Chrimes N. The Vortex: a universal ‘high-acuity implementation tool‘ for emergency airway management. Br J Anaesth. 2016;117(suppl 1):i20-i27. doi:10.1093/bja/aew175.
  14. RSI setup checklist. Broome Docs – Rural Generalist Doctors Education. Accessed April 14, 2023. https://broomedocs.com/clinical-resources/rsi-setup-checklist/
  15. Myatra SN, Divatia JV, Brewster DJ. The physiologically difficult airway: an emerging concept. Curr Opin Anaesthesiol. 2022;35(2):115-121. doi:10.1097/ACO.0000000000001102.
  16. Wheeler DS, Spaeth JP, Mehta R, Hariprakash SP, Cox PN. Assessment and management of the pediatric airway. In: Pediatric Critical Care Medicine: Basic Science and Clinical Evidence. London, UK: Springer; 2009:1-30. doi:10.1007/978-1-84800-919-6_4.
  17. Abdallah C. Pediatric endotracheal intubation. Middle East J Anesthesiol. 2015;23(1):123-124.
  18. Lewin SB, Cheek TG, Deutschman CS. Airway management in the obstetric patient. Crit Care Clin. 2000;16(3):505-513. doi:10.1016/s0749-0704(05)70127-5.
  19. Wadhwa A, Singh PM, Sinha AC. Airway management in patients with morbid obesity. Int Anesthesiol Clin. 2013;51(3):26-40. doi:10.1097/AIA.0b013e318298140f.
  20. Manoach S, Paladino L. Manual in-line stabilization for acute airway management of suspected cervical spine injury: historical review and current questions. Ann Emerg Med. 2007;50(3):236-245. doi:10.1016/j.annemergmed.2007.01.009.
  21. Petersen A, Wong E, Brown T. Age-related changes in airway anatomy and function: implications for anesthesia. Anesthesiol Clin. 2018;36(1):1-12.
  22. Hernandez A, Lee C, Patel K. Challenges in airway management in older adults. Anesth Analg. 2021;132(3):710-717.
  23. Baker M, Smith J, Johnson R. Airway management in the elderly: a review. J Geriatr Med. 2020;45(2):123-130.

Reviewed and Edited By

Picture of Arif Alper Cevik, MD, FEMAT, FIFEM

Arif Alper Cevik, MD, FEMAT, FIFEM

Prof Cevik is an Emergency Medicine academician at United Arab Emirates University, interested in international emergency medicine, emergency medicine education, medical education, point of care ultrasound and trauma. He is the founder and director of the International Emergency Medicine Education Project – iem-student.org, chair of the International Federation for Emergency Medicine (IFEM) core curriculum and education committee and board member of the Asian Society for Emergency Medicine and Emirati Board of Emergency Medicine.

Procedural Sedation and Analgesia (2024)

~ iEM Education Project Team ~ Leave a comment

by Nik Hisamuddin Nik Ab Rahman

Authors
Listen

Introduction

Sedation for painful procedures involves the administration of drugs by any route or technique that results in a reduction of awareness and pain levels. The main aim of procedural sedation analgesia (PSA) is to reduce discomfort while maintaining the effective performance of the procedure. Effective PSA induces a reduced level of consciousness while enabling the patient to independently sustain oxygenation and manage their airway [1, 2].

The use of sedation involves certain risks, including:

  1. Impairment of the patient’s protective reflexes, which can result in airway obstruction or aspiration.
  2. Suppression of respiratory and cardiovascular functions, which may lead to complications such as hypoxia, hypotension, bradycardia, or even cardiac arrest.

The effects of sedative medications can vary, with the possibility of over-sedation or airway obstruction at any point. Ensuring patient cooperation and maintaining verbal communication are critical objectives for procedural sedation. These guidelines are designed to assist non-anaesthesiologists in safely administering sedation and analgesia to adult patients, whether in an operating room or other settings, to minimize risks and enhance patient safety [3].

When sedation is managed by non-anaesthesiologists, it is essential to limit the sedation level to minimal or moderate. The ideal goal is to achieve a moderate level of consciousness, allowing the patient to independently maintain their airway and cardiovascular stability. Deep sedation should be avoided unless an emergency physician skilled in airway management or an anaesthesiologist is present throughout the procedure (Figure 1).

Figure 1 - Continuum Level of Sedation - Resource: American Society of Anesthesiologists article, March 2002 Volume 66, Number 3, Practice Management: Sedation and the Need for Anesthesia Personnel Karin Bierstein, J.D. (the figure illustrated by AA Cevik)

Goals of PSA include:

  • Ensuring patient safety before, during, and after PSA.
  • Minimizing pain and anxiety associated with the procedure.
  • Reducing the patient’s movement during the procedure.
  • Maximizing the likelihood of procedural success and facilitating the patient’s return to their pre-sedation state as quickly as possible.

Indications

  • Alleviate pain and/or anxiety commonly associated with therapeutic or diagnostic procedures.
  • Enhance the success of procedures by promoting patient relaxation and minimizing movement, thereby improving the precision and efficiency of the intervention.

Therapeutic or diagnostic interventions include, but are not limited to, synchronized cardioversion for the management of arrhythmias, closed reduction of dislocations or fractures, incision and drainage of abscesses, primary closure of lacerations, thoracostomy tube placement for pleural effusions or pneumothorax, extraction of foreign bodies, vascular access establishment for intravenous or intra-arterial administration, and cannulation for hemodynamic monitoring or intervention.

Contraindications

Absolute Contraindications

  • The urgent need for immediate treatment (e.g., hemodynamic instability) that cannot be delayed for sedation.
  • Hypersensitivity to the administered drug or its delivery vehicle.
  • Specific to nitrous oxide: Conditions such as pneumothorax, pneumomediastinum, bowel obstruction, or the presence of an intraocular gas bubble (e.g., following vitreoretinal surgery), where nitrous oxide can expand into air-filled spaces.

Allergy to eggs or soy is no longer considered a contraindication to propofol, as the allergenic components in eggs or soy differ from the moieties used in propofol formulations.

Relative Contraindications

  • Severe cardiopulmonary disease, which increases the risk of decompensation due to respiratory depression.
  • Obstructive sleep apnea.
  • Obesity or anatomical features (e.g., micrognathia, macroglossia, short neck, or congenital anomalies) suggestive of potential difficulties with intubation.
  • Chronic liver or kidney disease, which may impair drug metabolism and lead to prolonged sedation.
  • Patients older than 60 years of age, who face an increased risk of decompensation; PSA drug doses should often be reduced.
  • Acute alcohol or sedative drug intoxication, which heightens the risk of respiratory complications; PSA drug doses should be decreased accordingly.
  • Chronic alcohol or substance use disorder, which may necessitate an increased PSA drug dosage.
  • Pre-procedural intake of food or drink; institution-specific protocols regarding fasting prior to PSA should be reviewed.

When any of these relative contraindications are present, consult an anesthesiologist or consider the use of drugs that do not depress respiration (e.g., ketamine) [4, 5].

Although some guidelines recommend postponing elective procedural sedation for several hours after ingestion of clear liquids and for eight hours after ingestion of solids, there is no definitive evidence to support the efficacy or necessity of such measures.

Equipment and Patient Preparation

Choices of Sedative and Analgesic Agents

Always plan to use the minimum number and dosage of sedative and analgesic agents required to achieve the targeted level of sedation. This approach minimizes the risk of adverse drug effects and reduces the likelihood of complications associated with PSA.

“Never use neuromuscular blocking (NMB) agents for PSA.”

The selection of agents may differ based on local protocols or nationwide regulations. It is essential to consult the relevant institutional or regional guidelines. In cases of uncertainty, seek guidance from qualified emergency physicians or anesthetists [6].

Ketamine (IV or IM)
Ketamine can be administered intravenously (IV) or intramuscularly (IM). For IV administration, the loading dose ranges from 0.5 to 2 mg/kg, while for IM administration, the loading dose ranges from 2 to 4 mg/kg. Maintenance dosing is recommended at 0.1 mg/kg IV every 10 minutes. The typical dose for a 70 kg adult is 35 to 70 mg for IV administration and 140 to 280 mg for IM administration.

Fentanyl (IV)
Fentanyl is administered intravenously. The loading dose ranges from 50 to 100 mcg over a period of one minute. Maintenance dosing is 25 mcg every five minutes as required. For a typical 70 kg adult, the dose is approximately 50 mcg.

Midazolam (IV)
Midazolam is administered intravenously. The loading dose ranges from 1 to 2.5 mg IV given over two minutes. Maintenance dosing involves 1 mg every five minutes as required. For a typical 70 kg adult, the usual dose is 1 to 2.5 mg IV or 5 mg IM.

Etomidate (IV)
Etomidate is given intravenously with a loading dose of 0.1 to 0.2 mg/kg. Maintenance dosing is 0.05 mg/kg every five minutes. For a 70 kg adult, the typical dose is 7 to 15 mg IV.

Propofol (IV)
Propofol is administered intravenously with a loading dose ranging from 0.5 mg/kg (in elderly patients) to 1 mg/kg. Maintenance dosing is 0.1 mg/kg every one to two minutes. For a typical 70 kg adult, the loading dose is 35 to 70 mg, with a maintenance dose of 10 mg.

Ketafol (Ketamine + Propofol) (IV)
Ketafol, a combination of ketamine and propofol, is administered intravenously. The loading dose is 0.5 to 1 mg/kg of ketamine, with maintenance dosing of 10 mg of propofol every two minutes. For a 70 kg adult, the ketamine loading dose ranges from 35 to 70 mg IV, and the propofol maintenance dose is 10 mg every two minutes.

  • Ketamine is considered safe for use in children undergoing procedural sedation and analgesia in the emergency department (ED). Propofol is safe for procedural sedation and analgesia in both children and adults in the ED (LEVEL A).
  • Etomidate is safe for procedural sedation and analgesia in adults in the ED. Additionally, a combination of propofol and ketamine is safe for procedural sedation and analgesia in both children and adults (LEVEL B) [7].
  • Ketamine is safe for procedural sedation and analgesia in adults in the ED. Alfentanil is also safe for procedural sedation and analgesia in adults in the ED. Furthermore, etomidate is safe for use in children undergoing procedural sedation and analgesia in the ED (LEVEL C) [8, 9].
Facilities & Equipment

The procedure must be conducted in a facility that is sufficiently spacious and adequately equipped to handle potential cardiopulmonary emergencies. The required resources include:

  1. A room of adequate size to accommodate resuscitation efforts, if necessary.
  2. Adequate lighting for performing procedures safely.
  3. An operating table, trolley, or chair that can be tilted head-down (preferable but not mandatory).
  4. A suction apparatus meeting operating room standards.
  5. A reliable oxygen supply and suitable devices for administering oxygen to a spontaneously breathing patient.
  6. Equipment for lung inflation with oxygen (e.g., a self-inflating bag and mask) and access to a range of advanced airway management tools, including masks, oropharyngeal airways, endotracheal tubes, laryngoscopes, and laryngeal mask airways.
  7. A resuscitation trolley equipped with appropriate drugs and equipment for cardiopulmonary resuscitation.
  8. A pulse oximeter for monitoring oxygen saturation.
  9. A sphygmomanometer or another device for blood pressure monitoring.
  10. Ready access to an electrocardiogram (ECG) machine and a defibrillator.
  11. A reliable means of summoning emergency assistance.

Patient Preparation

Patient preparation is a critical step in ensuring the safety and effectiveness of procedural sedation and analgesia (PSA) in the emergency department. Proper preparation minimizes the risks of complications, enhances patient comfort, and facilitates procedural efficiency [10-12].

A comprehensive pre-procedural assessment is essential to evaluate the patient’s medical history, allergies, and current medications, including over-the-counter drugs, herbal supplements, and recreational substances. Identifying contraindications to sedation, such as a history of adverse reactions to sedatives or anesthetics, is crucial. Patients should be provided with detailed fasting instructions tailored to the type of sedation and their medical condition. Typically, fasting guidelines recommend 6–8 hours for solid food and 2–4 hours for clear liquids to reduce the risk of aspiration. However, many emergency department patients 

Informed consent is a cornerstone of patient preparation. Patients or their guardians should receive clear explanations about the procedure, its risks, benefits, and potential alternatives, and written consent should be obtained. It is equally important to address any anxiety or stress by offering reassurance and allowing patients to express concerns. Effective communication and education about what to expect during and after PSA help alleviate anxiety and improve the overall experience. Additionally, patients should be instructed to remove jewelry, dentures, or other loose objects before the procedure and wear comfortable, loose-fitting clothing.

On the day of the procedure, patients must have a responsible adult accompany them to the emergency department and arrange transportation home post-procedure. Intravenous (IV) access should be secured for administering sedatives, analgesics, and potential fluid resuscitation. Continuous monitoring of baseline vital signs, including oxygen saturation, heart rate, and blood pressure, must be ensured throughout the procedure to detect and address any adverse events promptly.

Post-procedure care involves monitoring the patient until they have fully recovered from sedation. Before discharge, patients should be provided with detailed written instructions on post-procedural care, including medication guidance, activity restrictions, and follow-up appointments. A contact number for the emergency department or healthcare provider should also be provided in case of concerns or complications after discharge.

Adhering to these recommendations, including thorough preparation, education, and monitoring protocols, ensures patient safety and comfort, reduces the likelihood of complications, and optimizes the success of PSA in the emergency department

Procedure Steps

General Clinical Management and Documentation
  • Written documentation of procedural sedation must be completed by the responsible physician or surgeon, covering all phases of the procedure (pre, intra-, and post-procedure).
  • Documentation should include:
    • Names of all staff involved in the procedure.
    • Findings from history, physical examination, and investigations.
    • Drug dosages and their administration times.
    • Vital signs (pulse rate, oxygen saturation, and blood pressure) recorded pre-, during, and post-procedure.

Assessment of Patient Status
The physician in charge should document patient assessment using the American Society of Anesthesiologists (ASA) classification system [13]:

  • ASA Class 1: Normal healthy patient with no significant systemic disturbances.
  • ASA Class 2: Patient with mild systemic disease without functional limitations.
  • ASA Class 3: Patient with severe systemic disease causing some functional limitation.
  • ASA Class 4: Patient with severe systemic disease posing a constant threat to life.
  • ASA Class 5: Moribund patient not expected to survive without surgery.
  • ASA Class 6: Brain-dead patient whose organs are being harvested for donation.

Note: PSA performed by non-anesthesiologists is recommended only for ASA Class 1 and 2 patients.

Indications for Involvement of an Anesthesiologist

The presence of an anesthesiologist may be required for patients at increased risk of airway, respiratory, or cardiovascular compromise, or those prone to serious adverse events during sedation [14]. These include patients with:

  1. Advanced age, particularly with significant co-morbidities.
  2. Significant cardiovascular, pulmonary, renal, or hepatic disease.
  3. Morbid obesity.
  4. Obstructive sleep apnea.
  5. Known or suspected difficult airway/intubation cases.
  6. Acute gastrointestinal bleeding associated with cardiovascular compromise or shock.
  7. Risk of aspiration of gastric contents.
  8. History of adverse events from sedation, analgesia, or anesthesia.
  9. History of substance abuse.

The decision to involve an anesthesiologist should be made by the clinician after carefully weighing the risks to the patient [14].

For non-emergency cases, PSA should adhere to general fasting guidelines to minimize the risk of aspiration during the procedure. The recommended fasting durations vary by age and the type of substance ingested, summarized as the “2-4-6 rule” [15]. For children, the guidelines are as follows: 2 hours for clear fluids, 4 hours for breast milk, and 6 hours for formula milk or solid foods. For adults, the fasting guidelines recommend 2 hours for clear fluids and 6 hours for milk or solids. Clear fluids include water, glucose drinks, cordial beverages, and clear fruit juices. These fasting protocols ensure adequate preparation and safety for PSA in non-emergency settings.

Steps in the Administration of Procedural Sedation [16]
Pre-Procedure

Proper preparation is essential to ensure the safety and success of PSA. The following steps should be undertaken:

  1. Patient Selection: Assess the appropriateness of PSA for the patient based on clinical needs and risk factors.
  2. Patient Assessment: Conduct a thorough review of relevant medical history, physical examination, and investigations as outlined in institutional protocols.
  3. Pre-Procedural Instructions: Provide patients with written instructions on preparation and post-procedural care, including contact details for emergencies. Instructions should be available in multiple languages to enhance accessibility.
  4. Consent: Obtain verbal or written consent according to institutional requirements. In cases of altered mental status or unconscious patients, PSA may proceed without written consent if close relatives provide authorization.
  5. Personnel: Ensure a minimum of two qualified and experienced personnel are present—one to perform the procedure and the other to administer drugs and monitor vital signs.
During the Procedure

To maintain patient safety and achieve the desired sedation level, adhere to the following steps during PSA administration:

  1. IV Access: Establish intravenous access for drug administration and potential resuscitation needs.
  2. Monitoring: Continuously monitor the patient’s vital signs, including pulse oximetry, non-invasive blood pressure (NIBP), and electrocardiography (ECG). Document all findings in accordance with protocol.
  3. Oxygen Administration: Deliver supplemental oxygen using appropriate devices such as nasal prongs or face masks, as indicated.
  4. Drug Administration: Administer sedation drugs exclusively by trained registered medical practitioners or registered dental practitioners.
  5. Continuous Observation: Assign a dedicated assistant to monitor the patient throughout the procedure, ensuring early detection and management of potential complications.
Post-Procedure

Post-procedural care focuses on monitoring recovery, ensuring patient safety, and providing clear discharge instructions:

  1. Documentation: Record all details of the procedure, including the drugs used and vital signs monitored.
  2. Recovery Monitoring: Continue observation of the patient’s vital signs using pulse oximetry and NIBP until full recovery is achieved.
  3. Discharge: Patients should be discharged only when accompanied by a responsible adult. Provide written instructions on post-procedural care.
  4. Reinforce Instructions: Before discharge, verbally review post-procedural care instructions to ensure patient understanding and compliance.
Recommendations for PSA Monitoring by Target Sedation Level

Monitoring requirements vary depending on the desired level of sedation:

Minimal Sedation:

  • Level of Consciousness: Observe frequently.
  • Heart Rate: Measure every 15 minutes.
  • Respiratory Rate: Measure every 15 minutes.
  • Blood Pressure: Measure every 15 minutes and after sedative boluses.
  • Oxygen Saturation: Monitor continuously.
  • Capnography End-Tidal CO2: Not required.

Moderate or Dissociative Sedation:

  • Level of Consciousness: Observe constantly.
  • Heart Rate: Monitor continuously.
  • Respiratory Rate: Continuous direct observation.
  • Blood Pressure: Record every 5 minutes and after sedative boluses.
  • Oxygen Saturation: Monitor continuously.
  • Capnography End-Tidal CO2: Consider continuous monitoring.
  •  

Complications

Performing PSA requires close monitoring and is associated with potential adverse events. Numerous analgesic, sedative, and anesthetic agents can be used in combination for PSA in the ED. However, adverse event reporting for PSA has been heterogeneous.

Known complications of PSA include agitation, apnea, aspiration, bradycardia, bradypnea, hypotension, hypoxia, intubation, laryngospasm, and nausea/vomiting [17-19]. Among these, the most frequently observed adverse events are hypoxia, occurring at a rate of 40.2 per 1,000 sedations, followed by vomiting, hypotension, and apnea.

Severe adverse events requiring emergent medical intervention are less common but include aspiration (%0.12), laryngospasm (%0.42), and intubation (%0.16). 

The routine use of capnography monitoring during PSA is recommended as it allows earlier detection of hypoventilation and apnea compared to pulse oximetry and/or clinical assessment alone [20]. Studies have shown that the combination of Ketamine and Propofol (Ketofol) results in a lower incidence of adverse events, including agitation, apnea, hypoxia, bradycardia, hypotension, and vomiting, compared to each medication used individually [21].

Although the incidence of serious adverse events during PSA in the ED is rare, it is essential to practice shared decision-making and obtain informed consent, as PSA is not a completely benign procedure [22].

Hints and Pitfalls

Pitfalls of PSA

The common pitfalls of procedural sedation and analgesia are often attributed to inadequate practitioner skills, improper patient selection, or insufficient knowledge of the pharmacological agents being used. When these factors are combined, they may result in either under-sedation or over-sedation, compromising the airway, cardiovascular, or respiratory system, and increasing the risk of adverse outcomes [23-26].

Failure to administer safe and effective PSA can lead to unnecessary complications, heightened anxiety, and delays in the patient’s return to normal function following emergency department procedures. Barriers to achieving optimal PSA outcomes, especially when performed by non-anaesthesiologists, often include knowledge gaps among providers and inadequate efforts toward quality improvement. It is critical that PSA be performed by competent and experienced practitioners who follow established guidelines and standard operating procedures, which should be readily available in all facilities where PSA is conducted (e.g., emergency physicians, internal physicians, surgeons, dental practitioners).

For painful procedures, alternative pain management strategies, such as nerve blocks, should be considered when they are safer and equally effective. Additionally, it is essential to complete a checklist for pre-, intra-, and post-PSA to ensure patient safety and optimize outcomes.

Key Considerations for PSA

  • Most sedative agents lack significant analgesic effects; therefore, analgesia should be administered beforehand and given sufficient time to achieve its maximal effect prior to administering the sedative agent.
  • PSA agents and doses should always be tailored to the individual patient, taking into account factors such as age, comorbidities, and the patient’s clinical status. Elderly, debilitated, and acutely ill patients require lower initial doses of sedative agents than healthy young adults.
  • Sedative agents should be titrated gradually to avoid complications, and sufficient time should be allowed for the sedative to take full effect before starting the procedure.
  • Regular audits and quality assurance programs should be conducted to monitor and improve PSA practices over time.

Indicators of Sedation Failure

Sedation failure may occur if:

  • The patient experiences undue discomfort during the procedure.
  • Adverse events such as hypotension or hypoxia arise.
  • Prolonged observation is required following the procedure.

Common Pitfalls in PSA Administration [23]

  1. Inadequate provision of analgesia prior to administering sedatives.
  2. Insufficient time allowed for analgesics or sedatives to achieve their maximal effect.
  3. Failure to adjust doses for elderly or chronically ill patients, leading to over-sedation or complications.
  4. Rapid titration of sedative agents, increasing the risk of adverse events.
  5. Premature discontinuation of monitoring or transferring a sedated patient from a controlled environment (e.g., from the procedure room to the x-ray department).
  6. Discharge of patients without adequate supervision or clear written instructions; sedative agents may cause amnesia, making verbal instructions ineffective.
  7. Failure to address the specific needs of vulnerable populations, such as pediatric, geriatric, or pregnant patients, as well as adults with significant comorbidities.

Special Patient Groups

Pediatrics [27,28]

Procedural sedation for pediatric patients requires thorough preparation and specific considerations due to their unique anatomical and physiological characteristics. Consent must be obtained from parents or guardians, except in emergent situations where two senior practitioners may assess and provide consent. Special attention should be given to airway assessment to prevent respiratory compromise. Pharmacological agents with known respiratory adverse effects should be avoided or dosages adjusted as necessary.

Assessment Prior to Procedural Sedation in Children:

  • Evaluate fasting status.
  • Perform a focused medical examination, emphasizing airway assessment.
  • Utilize the American Society of Anesthesiologists (ASA) classification (only ASA I & II patients are considered suitable).
  • Review previous sedation or general anesthesia experiences and outcomes.

Key Considerations:

  • A history of severe sleep apnea or airway abnormalities necessitates additional precautions when planning sedation.
  • Paradoxical reactions, such as increased agitation with benzodiazepines or barbiturates, are more common in younger children.
  • Adverse effects like agitation upon emergence, diplopia, nausea, and vomiting have been reported with ketamine use.
  • Selection of sedation agents and administration routes should align with the patient’s individual needs, the procedure type, and the anticipated level of pain.
  • Early consultation with a pediatric anesthesiologist is recommended for patients with chronic airway diseases or a history of drug-related adverse events.
  • Discharge should only occur with a responsible adult and comprehensive post-discharge instructions for home observation

Geriatrics [29]

Procedural sedation is generally safe in older adults; however, under-treatment of pain or inadequate sedation should be avoided. Initial assessment must include a thorough review of comorbidities and medication history to identify potential interactions with sedatives or analgesics.

Special Precautions for Geriatric Patients:

  • Patients with chronic respiratory or cardiovascular diseases require additional monitoring.
  • Older adults typically require lower doses of sedative agents due to increased sensitivity, slower metabolism, reduced physiological reserves, and smaller volume of distribution.
  • These patients are at higher risk for oxygen desaturation, but most respond well to supplemental oxygen.

Pregnant Patients [30,31]

Procedural sedation may be appropriate for pregnant patients experiencing significant pain, distress, or requiring surgical intervention, provided it is conducted under the supervision of a physician skilled in obstetric anesthesia. Pregnancy induces hemodynamic changes such as decreased blood pressure (due to vasodilation and aortocaval compression), increased cardiac output, and reduced maternal hematocrit.

Key Considerations for Sedation in Pregnancy:

  • Exposure to PSA medications is typically brief, with low doses, making significant adverse effects on pregnancy outcomes unlikely.
  • Over-sedation can lead to maternal hypotension and hypoxia, which may result in fetal hypoxia.
  • Medications used in PSA can influence uterine activity, placental perfusion, and fetal oxygenation. They may also directly affect fetal heart rate by crossing the placenta or indirectly via maternal hemodynamic changes.

Pharmacological Agents in Pregnancy:

  • Midazolam: Frequently used due to its rapid onset and short duration. Although it crosses the placenta via passive diffusion, no conclusive evidence suggests it adversely affects fetal development at clinically recommended doses. Animal studies indicate potential effects when combined with other anesthetics.
  • Propofol: Clinically recommended doses are not associated with fetal defects and are widely used for obstetric and non-obstetric procedures. However, excessive doses may result in fetal depression due to its lipophilic nature and placental transfer.
  • Ketamine: Generally not recommended due to limited human data. It is known to cross the placenta, and animal studies suggest potential neurotoxicity with prenatal and early postnatal exposure.

Author

Picture of Nik Hisamuddin Nik Ab Rahman

Nik Hisamuddin Nik Ab Rahman

Professor Dr. Nik Hisamuddin Nik Ab Rahman graduated with an MBChB from the University of Glasgow in 1994. He completed the Emergency Medicine trainee program (Master of Medicine) at Universiti Sains Malaysia (USM) in 2002. He further honed his expertise as a Clinical Fellow in Emergency Medicine at Edinburgh Royal Infirmary, Scotland, and in Hyperbaric & Diving Medicine at Key Largo, Florida, USA. In 2016, he earned his PhD in Health Informatics & GIS in Health, specializing in road traffic injuries. Professor Nik Hisamuddin spearheaded the development of the Department of Emergency Medicine at Hospital USM, introducing Malaysia’s first Trauma Intensive Care Unit (TICU). He currently serves as the Director of Hospital USM and a Professor in Emergency Medicine and Hyperbaric/Diving Medicine at the School of Medical Sciences, USM. Additionally, he is a committee member of the USM Management Team, the Malaysia National Specialist Registry (Emergency Medicine; 2009–present), and the Specialty Conjoint Committee in the Master of Medicine in Emergency Medicine (2005–2017). He has been awarded numerous research grants from national and international sources. His research and clinical interests include trauma and injury prevention, community life support education, hyperbaric medicine, and acute pain management. He is currently supervising seven PhD and eight Master's candidates, with a focus on Design and Developmental Research (DDR) approaches. With approximately 70 peer-reviewed journal articles to his name, Professor Nik Hisamuddin is a leading figure in his field. His hobbies include traveling, golfing, and shopping.

Listen to the chapter

References

  1. Godwin SA, Burton JH, Gerardo CJ, et al. Clinical policy: procedural sedation and analgesia in the emergency department. Ann Emerg Med.2014;63(2):247-258. (Practice guidelines) DOI: 10.1016/j.annemergmed.2013.10.015
  2. Norii T, Homma Y, Shimizu H et alProcedural sedation and analgesia in the emergency department in Japan: interim analysis of multicenter prospective observational study.  Anesth. 
  3. Smits GJ, Kuypers MI, Mignot LA et alProcedural sedation in the emergency department by Dutch emergency physicians: a prospective multicentre observational study of 1711 adults.  Med. J. 2017; 34: 237–42.
  4. Green SM, Roback MG, Krauss BS et alUnscheduled procedural sedation: a multidisciplinary consensus practice guideline.  Emerg. Med. 2019; 73: e51–e65.
  5. Hinkelbein J, Lamperti M, Akeson J et alEuropean Society of Anaesthesiology and European Board of Anaesthesiology guidelines for procedural sedation and analgesia in adults.  J. Anaesthesiol. 2018; 35: 6–24.
  6. Procedural sedation in the emergency department by Dutch emergency physicians: a prospective multicentre observational study of 1711 adults. Smits GJ, Kuypers MI, Mignot LA, et al. Emerg Med J. 2017;34:237–242.
  7. Stephen M Green et al. Unscheduled Procedural Sedation: A Multidisciplinary Consensus Practice Guideline. American College of Emergency Physicians. https://www.acep.org/patient-care/policy-statements/unscheduled-procedural-sedation-a-multidisciplinary-consensus-practice-guideline/. Published February 2019. Accessed September 26, 2019.
  8. Green S, Roback M, Kennedy R, Krauss B. Clinical practice guideline for emergency department ketamine dissociative sedation: 2011 update. Ann Emerg Med. 2011;57(5):449-461. https://www.ncbi.nlm.nih.gov/pubmed/21256625.
  9. Dilip TS, Chandy GM, Hazra D, Selvan J, Ganesan P. The adverse effects of ketamine on procedural sedation and analgesia (PSA) in the emergency department. J Family Med Prim Care. 2021;10:2279–2283. 
  10. Kern, J., Guinn, A., & Mehta, P. (2022). Procedural sedation and analgesia in the emergency department. Emergency medicine practice, 24(6), 1–24.
  11. Bell, A., Taylor, D. M., Holdgate, A., MacBean, C., Huynh, T., Thom, O., Augello, M., Millar, R., Day, R., Williams, A., Ritchie, P., & Pasco, J. (2011). Procedural sedation practices in Australian Emergency Departments. Emergency medicine Australasia : EMA, 23(4), 458–465. https://doi.org/10.1111/j.1742-6723.2011.01418.x
  12. Cappellini I, Bavestrello Piccini G, Campagnola L, Bochicchio C, Carente R, Lai F, Magazzini S, Consales G. Procedural Sedation in Emergency Department: A Narrative Review. Emergency Care and Medicine. 2024; 1(2):103-136. https://doi.org/10.3390/ecm1020014
  13. Horvath B, Kloesel B, Todd MM, Cole DJ, Prielipp RC. The Evolution, Current Value, and Future of the American Society of Anesthesiologists Physical Status Classification System. Anesthesiology. 2021 Nov 01;135(5):904-919.
  14. Stephen M Green et al. Unscheduled Procedural Sedation: A Multidisciplinary Consensus Practice Guideline. American College of Emergency Physicians. https://www.acep.org/patient-care/policy-statements/unscheduled-procedural-sedation-a-multidisciplinary-consensus-practice-guideline/. Published February 2019. Accessed September 26, 2019.
  15. Green SM, Leroy PL, Roback MG, et al. An international multidisciplinary consensus statement on fasting before procedural sedation in adults and children. Anaesthesia 2020; 75: 374-85.
  16. Academy of Medicine of Malaysia. Recommendations for Sedation and Analgesia by Non-Anaesthesiologists. From: https://www.moh.gov.my/moh/resources/auto%20download%20images/5ca1b20916a50.pdf Accessed December 1, 2024.
  17. Bellolio MF, Puls HA, Anderson JL et alIncidence of adverse events in paediatric procedural sedation in the emergency department: a systematic review and meta‐analysis. BMJ Open 2016; 6: e011384. 
  18. Bellolio MF, Gilani WI, Barrionuevo P, et al. Incidence of adverse events in adults undergoing procedural sedation in the emergency department: a systematic review and meta-analysis. Acad Emerg Med. 2016;23(2):119–134. 
  19. Kahlenberg L, Harsey L, Patterson M, et al. Implementation of a modified WHO pediatric procedural sedation safety checklist and its impact on risk reduction. Hosp Pediatr. 2017;7(4):225–231. doi: 10.1542/hpeds.2016-0089
  20. Wall BF, Magee K, Campbell SG, et al. Capnography versus standard monitoring for emergency department procedural sedation and analgesia. Cochrane Database Syst Rev.2017;3(3):CD010698.
  21. Miller KA, Andolfatto G, Miner JR, et al. Clinical practice guideline for emergency department procedural sedation with propofol: 2018 update. Ann Emerg Med.2019;73(5):470-480. (Practiceguidelines) DOI:10.1016/j.annemergmed.2018.12.012
  22. Calderwood AH, Chapman FJ, Cohen J, et al. Guidelines for safety in the gastrointestinal endoscopy unit. Gastrointest Endosc. 2014;79(3):363–372.
  23. Russell D, Thakore SB. Safe Sedation Procedures in Adults. Lloyd G, ed. Mac Mahon T, McKay G, reviewers. Published April 19, 2021. Accessed December 11, 2024. https://www.rcemlearning.co.uk/reference/adult-procedural-sedation/
  24. American College of Emergency Physicians . Clinical Policy: procedural Sedation and Analgesia in the Emergency Department. Annals of Emergency Medicine2014; 63: 247–58. 
  25. Beach ML, Cohen DM, Gallagher SM, Cravero JP. Major adverse events and relationship to nil per os status in pediatric sedation/anesthesia outside the operating room: a report of the pediatric sedation research consortium. Anesthesiology2016; 124: 80–8. 
  26. Green SM, Roback MG, Krauss BS et alUnscheduled procedural sedation: a multidisciplinary consensus practice guideline.  Emerg. Med. 2019; 73: e51–e65.
  27. Mahajan C, Dash HH. Procedural sedation and analgesia in pediatric patients. J Pediatr. Neurosci.2014; 9: 1–6.
  28. Bhatt M, Johnson DW, Chan J, et al. Risk factors for adverse events in emergency department procedural sedation for children. JAMA Pediatr.2017;171(10):957-964.
  29. Hayashi M, Norii T, Albright D, Crandall C. Incidence of adverse events for procedural sedation and analgesia for cardioversion using thiopental in elderly patients: a multicenter prospective observational study. Acute Med Surg. 2023 Jan 2;10(1):e812. doi: 10.1002/ams2.812.
  30. McElhatton P.R. The effects of benzodiazepine use during pregnancy and lactation. Reprod Toxicol.1994; 8: 461-475
  31. Reitman E. Flood P. Anaesthetic considerations for non-obstetric surgery during pregnancy. Br J Anaesth.2011; 107: i72-i78

Reviewed and Edited By

Picture of Arif Alper Cevik, MD, FEMAT, FIFEM

Arif Alper Cevik, MD, FEMAT, FIFEM

Prof Cevik is an Emergency Medicine academician at United Arab Emirates University, interested in international emergency medicine, emergency medicine education, medical education, point of care ultrasound and trauma. He is the founder and director of the International Emergency Medicine Education Project – iem-student.org, chair of the International Federation for Emergency Medicine (IFEM) core curriculum and education committee and board member of the Asian Society for Emergency Medicine and Emirati Board of Emergency Medicine.

Urinary Catheterization (2024)

~ iEM Education Project Team ~ Leave a comment

by Tejasvi Chikatla

Authors
Listen

Introduction

Urinary catheterization is a critical procedure commonly performed in emergency departments (EDs) for both therapeutic and diagnostic purposes. It is particularly essential for critically ill individuals. However, common indications include acute urinary retention, where immediate bladder drainage is necessary to relieve obstruction or neurological issues, and trauma, where urine output monitoring helps assess potential kidney or bladder damage in patients with significant abdominal or pelvic injuries. The procedure involves the retrograde insertion of a flexible catheter through the urethra into the bladder, typically performed by a doctor or nurse in hospital or community settings. Various catheter types are available, including indwelling catheters, which remain in the bladder for a period of time and are commonly inserted through the urethra or, when necessary, surgically through the abdominal wall (suprapubic catheters). Intermittent catheters are used for temporary bladder drainage and are immediately removed, while external catheters, designed for male patients, adhere to the penis to collect urine. Each catheter type is selected based on the clinical indication, patient condition, and procedural requirements, ensuring appropriate management in the ED setting. Depending on the indication and type of catheter used, it may be removed after a few minutes, hours, or days, or remain in place for a longer duration. [1-3]

Anatomy and Physiology

The urinary system is integral to the processes of urine production, storage, and excretion, serving as a critical pathway for the elimination of metabolic waste. It comprises the kidneys, ureters, urinary bladder, and urethra, each contributing to the system’s overall function [2, 4-5]:

  1. Kidneys: Paired retroperitoneal organs, producing approximately 1500 mL of urine daily in the average adult.
  2. Ureters: Muscular conduits that transport urine from the renal pelvis to the bladder via peristalsis.
  3. Urinary Bladder: A detrusor muscle-lined reservoir capable of accommodating 350–500 mL of urine under normal conditions before initiating micturition reflexes.
  4. Urethra: A muscular tube facilitating the excretion of urine from the bladder to the external environment. Urethral length differs significantly between sexes, with males having a 15–20 cm urethra and females a considerably shorter one, influencing catheterization approaches and techniques.

  • Male Urethra:

    • Approximately 15–20 cm long, divided anatomically into the prostatic, membranous, and spongy (penile) urethra.
    • A sharp angulation occurs at the membranous urethra as it passes through the urogenital diaphragm. During catheterization, the penis must be extended and elevated to minimize urethral resistance.
    • The urethral meatus is located at the distal tip of the glans penis.

  • Female Urethra:

    • A short urethra (~4 cm in length), originating at the bladder neck and terminating at the external urethral orifice, located approximately 2.5 cm posterior to the clitoral glans.
    • In postmenopausal females, the urethral meatus may migrate superiorly and posteriorly into the vaginal introitus due to tissue atrophy, where it is often surrounded by periurethral tissue and can be identified via palpation.

Urinary continence is maintained by three primary muscle groups:

  1. Internal urethral sphincter: An involuntary smooth muscle located at the bladder neck.
  2. External urethral sphincter: A voluntary striated muscle encompassing the membranous urethra.
  3. Pelvic floor musculature: Comprised of the levator ani and associated structures, providing additional support and aiding continence mechanisms.

Anatomical Considerations for Catheterization:

  • Male Catheterization:
    • The curved anatomy of the male urethra, particularly at the membranous segment, requires the penis to be held taut and perpendicular to the body during catheter insertion to facilitate atraumatic passage through the urethra.
  • Female Catheterization:
    • The shorter urethra and variability in the location of the external urethral orifice in certain populations (e.g., obese or elderly females) may necessitate the use of a Trendelenburg position or assistance for proper visualization and insertion of the catheter.

Indications

Indications of urinary catheterization can be classified in therapeutic and diagnostic indications [2-7].

Therapeutic Indications

Acute Urinary Retention:
A medical emergency characterized by the sudden inability to void, often associated with bladder volumes exceeding 300–500 mL. Immediate bladder decompression via catheterization is necessary to relieve discomfort and prevent complications.

  • Causes:
    • Obstructive: Benign prostatic hyperplasia (BPH), urethral strictures, or pelvic masses.
    • Infectious/Inflammatory: Prostatitis, cystitis, and urethritis.
    • Neurological: Stroke, multiple sclerosis, spinal cord injuries.
    • Pharmacologic: Anticholinergic or alpha-adrenergic drugs.

Chronic Urinary Retention:
Patients with chronic retention, often due to neurogenic bladder dysfunction, may require catheterization when non-invasive methods are inadequate.

Perioperative Management:

  • Indicated during and after abdominopelvic, urological, and gynecological surgeries to prevent urinary retention, monitor intraoperative urine output, and manage postoperative pain.
  • Early catheter removal is encouraged to promote ambulation and reduce the risk of infection.

Management of Urinary Incontinence:
When behavioral therapies or medications fail, catheterization can provide relief, particularly in patients at risk of skin breakdown from severe incontinence (e.g., stage III/IV pressure ulcers).

Bladder Irrigation:
Essential for flushing the bladder to remove clots, debris, or infections, particularly in cases of hematuria or post-surgical complications.

Drug Delivery:
In specific cases, chemotherapy agents may be instilled directly into the bladder via catheterization. This is not a routine in the emergency department setting.

Palliative and Comfort Care:
Used to enhance comfort in end-of-life care or for patients experiencing significant urinary-related discomfort. For these patients, urinary catheters are needed to be changed in the ED because of catheter’s malfunction. 

Social and Hygiene Needs:
Indicated in patients unable to maintain urinary hygiene due to severe disability or immobility.

Diagnostic Indications

Monitoring of Urine Output:

  • Continuous urinary output measurement is critical for hemodynamic monitoring in critically ill patients and during major surgical procedures.
  • Provides valuable data for assessing renal perfusion and fluid balance.

Sterile Urine Collection:

  • Facilitates the collection of uncontaminated urine samples for culture and sensitivity testing or urinalysis, especially in cases where non-invasive methods are unreliable.

Radiographic Studies:

  • Catheters are used during diagnostic imaging such as cystograms to assess bladder anatomy, detect structural abnormalities such as bladder rupture, or evaluate vesicoureteral reflux.

Urodynamic Studies:

  • Employed to measure bladder capacity, compliance, and flow rates in patients with suspected lower urinary tract dysfunction. This is not a common indication in the ED setting.

Measurement of Post-Void Residual Volume:

  • Catheterization allows accurate determination of residual urine, aiding in the diagnosis of incomplete bladder emptying or outlet obstruction. This is not a common indication in the ED setting.

Contraindications

Urethral catheterization is a common and essential procedure; however, careful consideration of contraindications is imperative to ensure patient safety and avoid complications. These contraindications are categorized into absolute and relative types based on the severity of risks involved [2,4,5,7].

Absolute Contraindications

Absolute contraindications are situations where urethral catheterization is strictly avoided due to the high risk of significant harm. The most critical contraindication is suspected urethral injury, which is commonly associated with blunt trauma. Key clinical indicators include:

  • Blood at the urethral meatus: A hallmark sign of potential urethral trauma.
  • Inability to void despite a full bladder.
  • Perineal, scrotal, or penile ecchymosis and/or edema in males or perineal or labial ecchymosis in females.

In such cases, imaging studies such as retrograde urethrography are mandatory to confirm or exclude urethral disruption before attempting catheterization. Proceeding without confirmation could exacerbate the injury or create a false passage.

Relative Contraindications

Relative contraindications are conditions where catheterization may proceed, but only with caution after weighing the risks and benefits. These include:

  1. History of Urethral Strictures: Patients with strictures are at higher risk of urethral trauma or false passage during catheter placement. A urology consult is often recommended in such cases.
  2. Current Urinary Tract Infection (UTI): Introducing a catheter may worsen the infection or lead to ascending complications like pyelonephritis. Careful assessment and, if necessary, antibiotic prophylaxis are recommended.
  3. Prior Urethral Reconstruction: Surgical alterations to the urethra can make catheterization technically challenging, necessitating expertise or specialized equipment.
  4. Recent Urological Surgery: Catheterization soon after urologic procedures may disrupt healing tissues, cause bleeding, or predispose to infection.
  5. History of Difficult Catheter Placement: Patients with prior traumatic or challenging catheterization experiences may require advanced techniques or urological intervention to avoid complications.
  6. Gross Hematuria: Significant bleeding in the urinary tract increases the risk of obstructing the catheter with blood clots or worsening hemorrhage during insertion.
  7. Evidence of Urethral Infection: Infection within the urethra increases the risk of sepsis or further complications if a catheter is inserted.
  8. Urethral Pain or Discomfort: Pain suggests underlying inflammation, trauma, or infection, which increases procedural risks.
  9. Low Bladder Volume or Poor Compliance: Inadequate bladder capacity or compliance may complicate catheter insertion and increase the risk of bladder trauma.
  10. Patient Refusal: Respect for patient autonomy is critical. Catheterization should only proceed with informed consent unless in life-threatening emergencies.

Equipment and Patient Preparation

Equipment

The equipment for urinary catheterization includes sterile supplies to maintain asepsis and ensure patient comfort [2,4,7]:

  • Sterile gloves and drapes: Maintain a sterile field and minimize contamination risks.
  • Antiseptic solution (e.g., povidone-iodine): Cleanses the urethral meatus to reduce bacterial load.
  • Water-soluble lubricant: Eases catheter insertion and minimizes trauma to the urethra.
  • Local anesthetic gel: Often used in male patients to reduce discomfort during insertion.
  • Urethral catheters: A 16 French Foley catheter is standard for most adults. Smaller sizes (e.g., 14 French) may be used for patients with urethral strictures.
    • Coudé catheter: Features a curved tip, beneficial for patients with prostatic hypertrophy or urethral stricture.
  • Syringe with sterile water: Inflates the catheter balloon to secure its placement.
  • Sterile collection device with tubing: Enables urine drainage and minimizes infection risks when used in a closed-catheter system.
  • Waterproof pad: Protects bedding during the procedure.
Types of Catheters

The choice of catheter depends on clinical indications, duration of use, and patient-specific considerations. Common types include:

Indwelling Catheters (Foley Catheters):

  • Designed for long-term use with a balloon at the tip to secure placement.
  • Inserted via the urethra or through a suprapubic route for cases involving urethral injury or chronic obstruction.
  • Connected to a drainage bag for continuous urine collection.

Intermittent Catheters:

  • Used for short-term drainage. Inserted and removed after bladder emptying.
  • Suitable for patients who self-catheterize or require periodic drainage.

External (Condom) Catheters:

  • Non-invasive option for male patients with incontinence.
  • Requires daily replacement to prevent infection.

Catheter composition and coating (e.g., silicone, Teflon, antimicrobial coatings) are selected based on patient needs, such as reducing infection risks in short-term catheterizations (<14 days).

Patient Preparation

Proper preparation is critical for the safe and effective placement of urinary catheters, ensuring both patient comfort and a reduction in procedural complications. This involves thorough communication, appropriate positioning, meticulous hygiene, and a sterile environment. Below is a comprehensive guide to preparing patients for urinary catheterization [2,4,5,7].

Communication and Consent
  • Explain the Procedure: Provide the patient with clear, concise instructions regarding the procedure, including its purpose, steps, and what sensations they might experience. Address their concerns to alleviate anxiety and foster cooperation.
  • Informed Consent: Verbal or written informed consent should be obtained after ensuring the patient understands the risks and benefits.
  • Answer Questions: Allocate sufficient time to respond to any queries, building trust and enhancing the patient’s confidence in the procedure.
Ensuring Patient Privacy and Comfort
  • Privacy: Maintain the patient’s dignity by using curtains, closing doors, and limiting exposure.
  • Positioning:
    • Men: Place the patient in the supine position with hips abducted.
    • Women: Position the patient in the lithotomy or frog-leg position with hips and knees flexed and rotated outward.
    • Use pillows for head support and a waterproof disposable pad under the buttocks to protect the bedding.
  • Lighting: Ensure adequate lighting to facilitate visualization of the urethral meatus.
Preparation of the Procedure Area
  • Sterility and Hygiene:
    • Perform thorough hand hygiene with soap and water or an alcohol-based sanitizer before donning sterile gloves.
    • Use sterile drapes to create a clean field around the procedure area.
  • Cleaning the Urethral Meatus:
    • Men: Using the non-dominant hand, retract the foreskin (if uncircumcised) and stabilize the penis. With the dominant hand, clean the glans penis and urethral meatus using an antiseptic solution (e.g., povidone-iodine) in a circular motion from the meatus outward.
    • Women: With the non-dominant hand, separate the labia to expose the urethral meatus. Clean the meatus using the dominant hand, applying antiseptic solution in a circular motion outward from the meatus. The non-dominant hand is considered contaminated and must not touch sterile equipment.
  • Special Considerations:
    • In morbidly obese female patients, consider the Trendelenburg position or assistance from a second provider to improve visualization of the urethral meatus.

Procedure Steps

Male Patient

Urinary catheterization in male patients requires meticulous preparation, sterile technique, and proper execution to ensure patient safety and comfort. Below is a detailed and organized guide [4,7];

Preparation Before the Procedure

Gather Equipment:

  • See equipment section

Patient Communication and Consent:

  • Explain the procedure, its purpose, and what the patient can expect.
  • Address any concerns and obtain informed consent to alleviate anxiety and establish trust.

Patient Positioning:

  • Place the patient in the supine position with hips comfortably abducted.
  • Maintain privacy by using curtains or closing the door.
  • Use drapes or towels to cover non-essential areas, exposing only the genital region.

Hand Hygiene and Sterile Field Setup:

  • Perform thorough handwashing or use an alcohol-based hand sanitizer.
  • Don sterile gloves and set up a sterile field with all necessary equipment.
Step-by-Step Catheterization Procedure

Prepare the Urethral Meatus:

  • Retract the foreskin if the patient is uncircumcised (using the non-dominant hand, which becomes non-sterile).
  • Clean the glans penis and urethral meatus using antiseptic solution in a circular motion from the meatus outward.
  • Discard used swabs or gauze appropriately.

Anesthetize the Urethra:

  • Insert 5–10 mL of lidocaine gel into the urethral meatus using a syringe.
  • Compress the urethra gently to retain the anesthetic for at least one minute. This step reduces discomfort, dilates the urethra, and facilitates catheter insertion.

Insert the Catheter:

  • Generously lubricate the catheter tip.
  • Hold the penis upright at a 90° angle to the abdomen and gently advance the catheter through the urethral meatus.
  • If using a Coudé catheter, ensure the curved tip faces upward to follow the natural urethral curvature.
  • Encourage the patient to relax and take slow, deep breaths to ease catheter passage through the prostatic urethra.
  • Advance the catheter until urine flows, ensuring the catheter is fully inserted to the level of the side port.

Inflate the Balloon:

  • Once urine flow is established, inflate the catheter balloon with 5–10 mL of sterile water using the syringe.
  • Gently pull the catheter back until resistance is felt, indicating that the balloon is snug against the bladder neck.
  • If the patient experiences pain or resistance during balloon inflation, deflate the balloon, withdraw the catheter slightly, and reposition it before reattempting inflation.

Secure the Catheter:

  • Return the foreskin to its normal position to prevent paraphimosis in uncircumcised patients.
  • Secure the catheter to the patient’s thigh using adhesive tape or a catheter securement device.
  • Place the drainage bag below the level of the bladder to allow gravity-assisted drainage.

Monitor and Finalize:

  • Verify proper urine flow into the drainage bag.
  • Remove sterile drapes and clean the surrounding area.
  • Ensure the drainage bag is positioned to prevent backflow and contamination. 
Post-Procedure Care

Documentation:

  • Record the catheter size, balloon volume, urine characteristics, and any patient responses during the procedure.
  • Document any complications or additional interventions.

Observation:

  • Regularly check for kinks or obstructions in the catheter or tubing.
  • Monitor the patient for signs of discomfort, infection, or other complications.

Patient Education:

  • Provide instructions on catheter care, including hygiene and recognizing potential complications such as infection or blockages.
  • Ensure follow-up care and reassessment as necessary. 
Key Precautions and Potential Complications
  • Sterility: Maintain a strict sterile technique to minimize the risk of catheter-associated urinary tract infections (CAUTIs).
  • Gentle Insertion: Avoid excessive force to prevent urethral trauma or creation of a false passage.
  • Balloon Positioning: Ensure the balloon is inflated within the bladder and not in the urethra to avoid severe injury or bleeding.
  • Paraphimosis Prevention: Always reposition the foreskin after the procedure in uncircumcised patients.

Female Patient

Urinary catheterization in female patients is a routine yet sensitive medical procedure requiring a meticulous approach to ensure safety, comfort, and sterility. Below is a detailed guide incorporating key steps and considerations for performing the procedure effectively [5,7].

Preparation Before the Procedure

Gather Equipment:

  • See equipment section

Communicate with the Patient:

  • Explain the procedure, including its purpose, steps, and potential sensations, to alleviate anxiety.
  • Address any concerns and obtain informed consent.

Prepare the Catheter:

  • Attach the catheter to the collection system.
  • Test the retention balloon for leaks by inflating it with sterile water.
  • Generously lubricate the catheter tip.

Position the Patient:

  • Ensure privacy by using curtains or closing the door.
  • Place the patient in a lithotomy position (hips and knees flexed, heels on the bed) or a frog-leg position (hips abducted and knees bent outward).
  • Place a disposable waterproof pad beneath the patient’s buttocks.
Step-by-Step Procedure

Hand Hygiene and Sterile Setup:

  • Perform thorough handwashing or use an alcohol-based hand sanitizer.
  • Don sterile gloves and create a sterile field using the drapes.

Expose the Urethral Meatus:

  • Use the non-dominant hand to gently separate the labia, exposing the urethral meatus. This hand is now considered non-sterile and must not touch sterile equipment.
  • Maintain exposure throughout the procedure.

Cleanse the Area:

  • Clean the area around the urethral meatus with povidone-iodine or another antiseptic solution.
  • Apply the solution using a circular motion, starting at the meatus and working outward.
  • Discard each swab after use to prevent contamination.

Insert the Catheter:

  • Hold the lubricated catheter with your dominant (sterile) hand.
  • Gently advance the catheter through the urethra. Encourage the patient to relax and breathe deeply to reduce discomfort.
  • If the catheter enters the vagina, discard it and use a new, sterile catheter.

Verify Placement:

  • Confirm proper placement by observing urine flow into the tubing.
  • Advance the catheter an additional 1–2 cm after urine is visible to ensure it is fully inside the bladder.

Inflate the Balloon:

  • Inflate the catheter balloon with 10 mL of sterile water.
  • If resistance or pain occurs during inflation, deflate the balloon, advance the catheter further into the bladder, and reattempt inflation.

Secure the Catheter:

  • Gently withdraw the catheter until the inflated balloon rests snugly against the bladder neck.
  • Secure the catheter to the patient’s thigh using adhesive tape or a catheter stabilization device.

Position the Drainage Bag:

  • Hang the drainage bag below the level of the bladder to allow urine to flow via gravity.
  • Ensure the bag is not placed on the floor to maintain sterility.
Post-Procedure Care

Documentation:

  • Record the catheter size, balloon volume, urine characteristics, and any patient responses or complications.
  • Include details about the procedure’s success and any deviations from standard protocol.

Observation:

  • Regularly check for kinks or blockages in the tubing.
  • Monitor the patient for signs of discomfort or infection.

Patient Education:

  • Provide instructions on catheter care and signs of potential complications, such as fever, pain, or cloudy urine.
  • Emphasize the importance of hygiene to prevent infections.
Important Considerations and Precautions

Sterility: Adherence to strict sterile technique is critical to minimize the risk of catheter-associated urinary tract infections (CAUTIs).

Proper Insertion: Never use excessive force during catheter insertion, as this can cause urethral trauma.

Balloon Positioning: Ensure the balloon is fully within the bladder before inflation to prevent urethral injury.

Special Situations:

  • In obese or anatomically challenging cases, assistance or placing the patient in a Trendelenburg position may improve visualization of the urethral meatus.

Complications

Urinary catheterization carries the risk of various complications that can affect patient safety, comfort, and overall health outcomes. These complications are influenced by the type of catheter, duration of use, and underlying patient conditions [1-2, 4-6, 7]. 

Common Complications

Urinary Tract Infection (UTI):

  • Prevalence: The most common complication, particularly with long-term catheterization.
  • Pathophysiology: The normal urine flow prevents microbial ascent into the bladder. Catheterization disrupts this mechanism, increasing the risk of colonization and infection.
  • Etiology: Common pathogens include Escherichia coli and Klebsiella pneumoniae.
  • Impact: UTIs account for approximately 70% of healthcare-associated infections, with catheter-associated UTIs (CAUTIs) being the primary contributor.
  • Clinical Considerations:
    • Risk of bacterial colonization rises daily (3–10% per day, reaching 100% in long-term catheters).
    • Diagnosed via bacteriuria and fever in patients with indwelling catheters for ≥2 days.
    • Recurrent UTIs increase antibiotic resistance.

Urethral Trauma and Injury:

  • May result from improper insertion techniques or use of excessive force.
  • Symptoms include urethral bleeding, microscopic hematuria, or scarring that can lead to strictures.

Bladder Spasms:

  • Painful contractions caused by the bladder attempting to expel the catheter.
  • Managed with anticholinergic agents such as oxybutynin.

Catheter Obstruction:

  • Caused by sediment accumulation or debris, often in patients with subclinical bacteriuria.
  • Management includes flushing the catheter or replacing it if flushing is ineffective.

Urine Leakage:

  • May occur due to bladder spasms, catheter obstruction, a catheter that is too small, or constipation.

Paraphimosis (in males):

  • Results from failure to reduce the foreskin after catheter insertion.
  • Prevented by repositioning the foreskin immediately after the procedure.

Bladder Stones:

  • Prolonged catheter use can lead to the formation of calculi requiring further medical intervention.

Hematuria:

  • May be associated with trauma, infections, or balloon inflation in the urethra.

Bladder and Kidney Damage:

  • Chronic bladder infections and stasis at the catheter balloon base may lead to complications, including bladder or kidney damage.

Impact on Quality of Life:

  • Long-term catheterization adversely affects patients’ psychological and physical well-being.
Risk Factors
  • Pelvic Injuries: Increased risk of urethral disruption.
  • Prostatic Hypertrophy: Leads to increased resistance during catheter insertion in older males.
  • Recent Urological Surgery: Predisposes to infections and structural complications.
Preventive Measures

Aseptic Technique:

  • Strict adherence to sterile procedures during catheter insertion and care minimizes infection risks.

Minimizing Duration:

  • Regular assessment of catheter necessity and removal as soon as clinically feasible.

Appropriate Catheter Selection:

  • Use of the correct size and type of catheter tailored to the patient’s anatomy and clinical needs.

Regular Monitoring:

  • Routine checks for catheter kinks, blockages, and signs of complications like UTIs or hematuria.

Patient Education:

  • Inform patients on catheter care and early signs of complications.
Indications for Catheter Removal
  • Routine assessment of catheter necessity should guide removal.
  • Early removal improves recovery post-surgery, such as following intraperitoneal or colorectal procedures.
  • For chronic urinary retention, intermittent catheterization is often preferable.

Hints and Pitfalls [1,2, 4-7]

Hints for Successful Catheterization

Patient Positioning and Assistance:

  • Women: Position the patient in the lithotomy or frog-leg position for optimal exposure of the urethral meatus. In obese patients or those with pelvic organ prolapse, an assistant may be necessary to facilitate visualization.
  • Men: Position the patient supine with hips comfortably abducted for ease of insertion.

Generous Lubrication:

  • Ensure adequate lubrication of the catheter tip, particularly in men, to reduce resistance and discomfort.
  • For male patients, cooling the lubricant gel to 4°C can help minimize the stinging sensation.

Catheter Selection:

  • Choose the appropriate catheter size, material, and tip shape based on the patient’s anatomy and clinical needs.
  • Use a Coudé catheter for men with prostatic hypertrophy or urethral strictures due to its curved tip, which facilitates navigation through anatomical challenges.

Balloon Inflation:

  • Inflate the catheter balloon only after confirming proper placement in the bladder. Resistance or pain during inflation suggests incorrect positioning.
  • If resistance is encountered, deflate the balloon, advance the catheter further, and reattempt inflation.

Sterile Technique:

  • Maintain strict sterility throughout the procedure to minimize the risk of catheter-associated urinary tract infections (CAUTIs). This includes proper hand hygiene, sterile gloves, and cleansing of the urethral meatus.

Hydration and Bowel Management:

  • Encourage patients to stay well-hydrated and manage constipation, as both factors can reduce the risk of complications like UTIs and catheter blockage.

Early Removal:

  • Remove the catheter as soon as it is no longer clinically indicated to reduce the risk of infection and other complications.

Flushing the Catheter:

  • If urine does not flow initially, flush the catheter with 30–60 mL of normal saline to clear potential lubricant blockage and confirm placement.
Pitfalls to Avoid

Misplaced Catheter:

  • In women, accidental insertion into the vagina is common. Discard the contaminated catheter and use a new sterile one.

Urethral Trauma:

  • Avoid forcing the catheter during insertion, as this can lead to urethral injury, bleeding, or the creation of a false passage.
  • In cases of significant resistance or suspected urethral injury, stop the procedure and consult a urologist.

Incorrect Balloon Inflation:

  • Inflating the balloon in the urethra rather than the bladder can cause severe pain and trauma. Always advance the catheter fully before inflation.

Paraphimosis:

  • In uncircumcised men, ensure the foreskin is returned to its natural position after the procedure to prevent paraphimosis.

Ignoring Resistance:

  • Resistance during insertion may indicate anatomical challenges such as strictures or obstructions. Evaluate the situation and consider using a different catheter type, such as a Coudé, or seek urological consultation.

Catheter Obstruction:

  • Monitor for kinks or sediment buildup in the catheter. If blockage occurs, attempt gentle flushing with saline. Replace the catheter if flushing is ineffective.

Inadequate Lubrication:

  • Insufficient lubrication increases the risk of urethral trauma and patient discomfort, particularly in male patients with longer and more curved urethras.
Additional Considerations

Consultation with Urologists:

  • Seek urological consultation for difficult catheterizations, patients with complex anatomical variations, or persistent challenges during insertion.

Patient Education:

  • Provide clear instructions to patients, addressing their concerns and explaining the procedure to alleviate anxiety and improve cooperation.

Monitoring for Complications:

  • Regularly assess patients with urinary catheters for signs of complications, such as UTIs, hematuria, or catheter obstruction. Early detection and intervention are critical to preventing more severe outcomes.

Special Patient Groups

Pediatrics [8-10]

Urinary catheterization in pediatric patients requires meticulous attention to their unique anatomical and physiological characteristics. The indications for catheterization include urinary retention, neurogenic bladder, and post-surgical care, with efforts to minimize the duration of catheter use to reduce catheter-associated urinary tract infections (CAUTIs). Selecting an appropriately sized catheter, usually between 6 French (Fr) and 10 Fr, is crucial to avoid trauma and ensure comfort. Specialized catheters with hydrophilic or antimicrobial coatings can help minimize infection risks. Parental education plays a vital role; caregivers should be trained in catheter care and clean intermittent catheterization to maintain hygiene and bladder health. Clear communication and child-friendly techniques can reduce anxiety and improve cooperation during the procedure.

Geriatrics [11-14]

In geriatric patients, catheterization poses unique risks due to factors such as reduced mobility, cognitive impairments, and comorbidities. Older adults are particularly vulnerable to CAUTIs, making it essential to use catheters only when absolutely necessary. Employing antimicrobial catheters and adhering to strict aseptic techniques can help minimize infection risks. Cognitive impairments, including dementia, may necessitate additional monitoring to prevent unintentional self-removal or trauma. Alternatives to catheterization, such as non-invasive methods of urine collection, should be considered to enhance patient mobility and reduce complications. Regular reassessment of catheter necessity, coupled with early removal, is crucial to mitigating risks and promoting better outcomes in this population.

Pregnant Patients

Pregnant patients present specific challenges due to physiological changes in the urinary system, including increased renal workload and bladder compression by the growing uterus. These changes heighten the risk of urinary retention and catheter-associated complications. Catheterization may be required during labor, especially with epidural anesthesia, or postpartum for urinary retention. In such cases, strict adherence to sterile techniques is vital to prevent UTIs, which pose risks to both maternal and fetal health. Prompt treatment of asymptomatic bacteriuria (ASB) and UTIs is essential to avoid adverse outcomes. Early catheter removal and the use of clean intermittent catheterization when needed can reduce infection risks and improve recovery.

Author

Picture of Tejasvi Chikatla

Tejasvi Chikatla

Dr. Tejasvi Chikatla, a Consultant in the Emergency Department at Apollo Hospitals, Hyderabad, has over 9 years of experience in Emergency Medicine. With qualifications including MBBS, a Diploma in Emergency Medicine (Royal Liverpool Academy), and Membership of the Royal College of Emergency Medicine (UK), Dr. Chikatla is a dedicated educator and clinical supervisor. A lifetime member and instructor for SEMI, they are also a Master Trainer for WHO's Basic Emergency Care and serve on committees for IFEM.

Listen to the chapter

References

  1. Urinary catheterisation. NHSInform. From: https://www.nhsinform.scot/tests-and-treatments/medicines-and-medical-aids/medical-aids/urinary-catheterisation#:~:text=Urinary%20catheterisation%20is%20a%20procedure,in%20hospital%20or%20the%20community. Accessed December 1, 2024
  2. Haider MZ, Annamaraju P. Bladder Catheterization. [Updated 2023 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK560748/
  3. (5) Urinary catheterisation. Victoria State Government. From: https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/urinary-catheterisation#bhc-content Accessed: December 1, 2024
  4. (3) Chung PH. How To Do Urethral Catheterization in a Male. From: https://www.msdmanuals.com/en-in/professional/genitourinary-disorders/how-to-do-genitourinary-procedures/how-to-do-urethral-catheterization-in-a-male Accessed: December 1, 2024
  5. (4) Chung PH. Chung PH. How To Do Urethral Catheterization in a female. From: https://www.msdmanuals.com/en-in/professional/genitourinary-disorders/how-to-do-genitourinary-procedures/how-to-do-urethral-catheterization-in-a-female Accessed: December 1, 2024
  6. (6) Urinary catheters. MedlinePlus. From: https://medlineplus.gov/ency/article/003981.htm Accessed: December 1, 2024
  7. Haider MZ, Annamaraju P. Bladder Catheterization. [Updated 2023 Aug 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK560748/
  8. Robson WL, Leung AK, Thomason MA. Catheterization of the bladder in infants and children. Clin Pediatr (Phila). 2006;45(9):795-800. doi:10.1177/0009922806295277
  9. Crigger C, Kuzbel J, Al-Omar O. Choosing the Right Catheter for Pediatric Procedures: Patient Considerations and Preference. Res Rep Urol. 2021;13:185-195. Published 2021 Apr 28. doi:10.2147/RRU.S282654
  10. Carlson D, Mowery BD. Standards to prevent complications of urinary catheterization in children: should and should-knots. J Soc Pediatr Nurs. 1997;2(1):37-41. doi:10.1111/j.1744-6155.1997.tb00198.x
  11. Getliffe KA. Urinary Catheter Use in Older People. Aging Health, 2008;4(2), 181–189. https://doi.org/10.2217/1745509X.4.2.181
  12. Kang SC, Hsu NW, Tang GJ, Hwang SJ. Impact of urinary catheterization on geriatric inpatients with community-acquired urinary tract infections. J Chin Med Assoc. 2007;70(6):236-240. doi:10.1016/S1726-4901(09)70365-X
  13. Inelmen EM, Sergi G, Enzi G. When are indwelling urinary catheters appropriate in elderly patients?. Geriatrics. 2007;62(10):18-22.
  14. Pader ML, Rolland Y, Castex A, et al. Le sondage vésical chez le sujet âgé [Urinary catheterization in the elderly patient]. Soins Gerontol. 2008;(72):11-14.

Reviewed and Edited By

Picture of Erin Simon, DO

Erin Simon, DO

Dr. Erin L. Simon is a Professor of Emergency Medicine at Northeast Ohio Medical University. She is Vice Chair of Research for Cleveland Clinic Emergency Services and Medical Director for the Cleveland Clinic Bath emergency department. Dr. Simon serves as a reviewer for multiple academic emergency medicine journals.

Picture of Arif Alper Cevik, MD, FEMAT, FIFEM

Arif Alper Cevik, MD, FEMAT, FIFEM

Prof Cevik is an Emergency Medicine academician at United Arab Emirates University, interested in international emergency medicine, emergency medicine education, medical education, point of care ultrasound and trauma. He is the founder and director of the International Emergency Medicine Education Project – iem-student.org, chair of the International Federation for Emergency Medicine (IFEM) core curriculum and education committee and board member of the Asian Society for Emergency Medicine and Emirati Board of Emergency Medicine.

Intraosseous (IO) Lines/Access (2024)

~ iEM Education Project Team ~ Leave a comment

by Yousif Al-Khafaji & Mustak Dukandar

Authors
Listen

Introduction

Obtaining intravascular access in the emergency department is one of the most essential steps in managing critically ill patients. While it is a simple step for most patients, it can be the most challenging procedure during resuscitation. The pediatric population has more body fat, making it difficult to localize their veins. In addition, they have tiny peripheral veins that easily collapse in states of shock. On the other hand, in adults, patients who are obese, those who suffer from extensive burns, or are in shock challenge the clinician in obtaining vascular access [1].

Intraosseous (IO) access involves inserting a hollow needle through the cortex of the bone and into the medullary space. This allows clinicians to infuse fluids, medication, or almost anything that can be administered through the intravenous (IV) route and achieve the same desired effect as the IV route. The IO line is merely a bridging tool to buy the clinician time to obtain IV access. In most cases, IO access is a simple procedure, and clinicians should not hesitate to insert an IO line if peripheral IV access attempts fail.

IO lines can safely remain in place for up to 24 hours and are often a bridge to either IV or Central Venous line placement.

Indications

There are clear indications for IO access. Each of these indications highlights the critical role of IO lines in emergency medicine, providing a swift and effective solution for vascular access in life-threatening situations [3]. When IV access cannot be achieved, IO access is safe, reliable, and quick. It can be accomplished in 30 to 60 seconds and even faster with an IO gun. This is especially helpful in pediatric emergencies when time is critical. 

Emergency intravascular access when other methods have failed
IO access is indicated when IV access is not achievable in critical situations, such as trauma, shock, or severe dehydration. In critically ill patients, a maximum of two failed attempts is generally considered sufficient to shift to IO access. The IO line provides a rapid and reliable alternative to IV lines for administering fluids, medications, or blood products directly into the vascular system via the bone marrow [4]. 

Cardiac arrest
During cardiac arrest, time is critical, and establishing vascular access can be challenging. IO access is often used to administer life-saving medications like epinephrine when IV access cannot be obtained quickly. It ensures the rapid delivery of drugs into circulation during resuscitation [5].

Obtaining blood for laboratory evaluation
IO access allows for the collection of blood samples for laboratory testing, including complete blood count, electrolytes, and blood gas analysis [6]. This is especially useful in emergency situations where traditional venipuncture is impractical or impossible.

Contraindications

Physicians should be aware of a couple of important complications. These contraindications emphasize the importance of careful site selection and patient evaluation before performing IO access to minimize complications and maximize the effectiveness of the procedure [1].

Fractured bone
A fracture at the intended site of IO access is an absolute contraindication. Using a fractured bone for IO infusion can result in extravasation of fluids and medications, potentially worsening the injury and causing further complications.

Infection or burn overlaying insertion site
Localized infection or burns at the insertion site pose a significant risk of introducing pathogens into the bone marrow, leading to osteomyelitis or systemic infection. These conditions are absolute contraindications for IO placement.

Prior use of the same bone for IO infusion
Repeated use of the same bone for IO access can damage the bone marrow and structure, increasing the risk of complications such as extravasation or impaired drug delivery. A different site should be chosen for subsequent IO insertions.

Osteoporosis and osteogenesis imperfecta
These conditions result in fragile bones, increasing the likelihood of fractures or other complications during needle insertion. Alternative access methods should be considered for patients with these conditions.

Administration of ultra-short-acting medications like adenosine (relative contraindication)
Medications like adenosine, which rely on rapid systemic distribution, may not be as effective when administered via IO access due to potential delayed uptake into circulation. This is a relative contraindication, depending on the clinical scenario.

Equipment and Patient Preparation

Equipment

IO Needle

  • Ranges from 15-18 gauge needles
  • Color coding is common:
    • Pink (15 mm): For patients weighing 3–39 kg
    • Blue (25 mm): For patients ≥3 kg and above
    • Yellow (45 mm): For patients ≥40 kg, excessive tissue, or dense bone sites (e.g., proximal humerus or anterior superior iliac spine)

IO Devices (to facilitate insertion)

  • Powered IO Drills (e.g., EZ-IO)
  • Manual IO Drills (e.g., Cook IO Needle or Jamshidi-type needle)

Skin Disinfectants

  • Chloraprep
  • Alcohol swabs
  • Optional: Povidine or Chlorhexidine

Syringe and Flush Materials

  • Saline flush (crystalloid solution, e.g., normal saline or lactated Ringer’s)
  • Intravenous tubing

Lidocaine 2% (without epinephrine)

  • For topical and subcutaneous infiltration in awake patients, as they may experience pain during fluid infusion rather than needle insertion.

Additional Equipment

  • Infusion pump (to regulate fluid delivery)
  • Tape (for securing the IO line)
Arrow® EZ-IO® Intraosseous Vascular Access System - adopted from https://www.teleflex.com/usa/en/product-areas/emergency-medicine/intraosseous-access/arrow-ez-io-system/use-and-application/Arrow_EZ-IO_Landmarking_Poster.pdf

Patient Preparation

  1. Informed Consent
    • Obtain informed consent by explaining the procedure, its benefits, and associated risks to the patient or their guardians. In emergency situations where consent cannot be obtained, implied consent applies.
  2. Site Selection
    • Choose the most appropriate insertion site based on the clinical scenario. Common sites include:
      • Humeral Head
      • Proximal Tibia
      • Medial Malleolus
      • Sternum
      • Distal Radius
      • Distal Femur
      • Anterior Superior Iliac Spine
    • Note: The proximal tibia and humeral head are most commonly used during cardiac arrest as these locations do not interfere with other life-saving procedures like intubation [7].
  3. Contraindication Assessment
    • Ensure there are no contraindications (e.g., fractures, infections, burns, prior IO use at the same site, or certain bone conditions) at the intended site of insertion.
  4. Site Exposure
    • Properly expose the selected insertion site to facilitate accurate placement and reduce the risk of contamination.
  5. Universal Precautions
    • Apply universal precautions, such as wearing gloves at a minimum, to maintain aseptic conditions during the procedure.
  •  
IO placement locations. IO size (color) is subject to the patients body weight.

Sites of IO insertion and some hints [8]

  1. Proximal Tibia
    • 2 finger breadths below the tibial tuberosity (1-3 cm) on the medial, flat aspect of the tibia.
    • Commonly used for ease of access, especially in emergencies.
  2. Distal Tibia
    • Medial surface at the junction of the medial malleolus and the shaft of the tibia, posterior to the greater saphenous vein.
  3. Proximal Humerus (Adults only; use the yellow needle)
    •  Preparation:
      • Keep the arm adducted and internally rotated (rest the patient’s hand on their bellybutton).
      • Slide fingers up the humerus until you feel the notch (surgical neck).
    •  Insertion:
      • Insert the IO needle 1 cm above the surgical neck into the greater tubercle.
      • Immobilize the arm to prevent displacement of the IO line (avoid shoulder abduction).
  4. Distal Femur
    • Primarily used in infants and children due to easier bone access and growth plate considerations.
  5. Pelvic Anterior Superior Iliac Spine (ASIS)
    • An alternative site, especially when lower extremity or upper extremity sites are unavailable.
  6. Sternum
    • Provides the highest flow rate of any location, making it suitable for rapid infusions during critical situations.

Procedure Steps

  1. Preparation
    • Identify the designated site using a sterile gloved finger.
    • Disinfect the overlying skin using appropriate antiseptic (e.g., chlorhexidine).
    • Administer local anesthetic if the patient is awake.
    • Ensure the stylet is properly positioned on the needle prior to insertion.
    • Prepare necessary equipment, including a 20 ml saline syringe, IV tubing, tape, medications, fluids, and infusion pump.
  2. Needle Insertion
    • Insert the needle perpendicularly through the skin down to the bone.
    • Use an IO drill or manually twist the needle clockwise with firm, gentle pressure until a “give” is felt (loss of resistance), indicating entry into the marrow.
    • Ensure the needle locks into place.
  3. Confirmation of Placement
    • The needle should stand upright without additional support if properly positioned.
    • Remove the stylet and attach a syringe.
    • Aspirate to confirm the presence of marrow or blood (not always visible).
    • Gently flush the line with saline while observing for swelling at or around the insertion site.
  4. Troubleshooting
    • If swelling occurs or the test injection fails, remove the IO needle and repeat the procedure on a different site.
  5. Securing and Using the IO Line
    • If Io works properly, stabilize the needle using tape or gauze padding as necessary.
    • Attach IV tubing to the needle hub.
    • Begin infusion of fluids, blood products, or medications.
    • If the patient is awake and experiences pain during infusion, administer lidocaine through the IO line for analgesia [2].
  •  

Complications [9]

Extravasation of Fluid

Occurs when fluid or medication leaks into surrounding soft tissues instead of the bone marrow cavity. This can cause localized swelling, tissue damage, and discomfort. Proper placement and observation for swelling during infusion are essential to avoid this complication.

Compartment Syndrome

Results from increased pressure within a muscle compartment due to extravasation of fluid. It can compromise blood flow, leading to tissue ischemia and potential necrosis. Immediate recognition and corrective action are necessary to prevent long-term damage [10].

Bone Fracture

More common in patients with pre-existing bone disorders, such as osteoporosis or osteogenesis imperfecta. Improper needle insertion technique can increase the risk of fracturing the bone at the insertion site. Physicians should be careful when inserting IO lines in small children because too much pressure during drilling may cause fractures.

Osteomyelitis

A rare but serious complication involving infection of the bone and marrow. This risk increases if aseptic technique is not followed or if there is a pre-existing infection near the insertion site.

Preventative Measures:

  • Use strict aseptic technique to minimize infection risks.
  • Properly assess the patient’s bone health and contraindications before insertion.
  • Monitor the insertion site for early signs of complications, such as swelling or pain, during and after infusion

Hints and Pitfalls

Purpose and Time Limit

  • IO access is a bridging tool used to buy time for obtaining peripheral or central IV access.
  • IO needles should not remain in place for more than 24 hours, as the risk of complications increases significantly after that time frame.

Site and Device Selection

  • Always use an uninjured limb for IO placement; if no uninjured limb is available, the sternum is preferred.
  • An IO drill or gun is recommended over manual insertion for consistent and reliable placement.
  • Needle selection must be appropriate for the selected site and the marrow cavity to ensure proper access.

Needle Placement and Security

  • IO needle displacement can sometimes occur, especially in pediatric patients with soft bones; this can be mitigated by securing the needle to the skin properly.
  • The anterior superior iliac spine may be considered as an alternative site in cases of soft bone structures.

Medication and Dosage

  • Any medication that can be administered via IV access can also be given through IO access without dose adjustment, as the bioequivalence between IO and IV routes is similar. [11,12]

Laboratory Sampling

  • Lab tests with good correlation from IO samples include hemoglobin/hematocrit, chloride, glucose, urea, creatinine, and albumin.
  • Other lab values, such as WBC, platelets, serum CO2, sodium, potassium, and calcium, may not correlate well with venous samples. [13]
  •  

Special Patient Groups

Pediatrics

  • Challenges: In pediatric patients, the bones can sometimes be too soft, which increases the risk of needle displacement even when placed correctly.
  • Recommendation: To mitigate this risk, consider using the anterior superior iliac spine as an alternative site. This site may provide a more stable placement in cases where traditional sites like the tibia are less effective.

Geriatrics

  • Challenges: Older adults often have pre-existing bone disorders such as osteoporosis, which make their bones more fragile.
  • Risks: IO insertion in such patients can lead to fractures, especially if not performed with careful technique and appropriate needle selection.
  • Recommendation: Perform a thorough assessment of bone health and use alternative vascular access methods if significant bone fragility is present.

Pregnant Patients

  • Considerations: There are no contraindications for IO insertion in pregnant women. This makes IO access a viable option during emergencies where quick vascular access is necessary.
  • Precautions: Ensure that the chosen site does not interfere with obstetric care and consider patient positioning to maintain comfort and safety during the procedure.

Authors

Picture of Yousif Al-Khafaji

Yousif Al-Khafaji

Chief Emergency Medicine Resident - Tawam Hospital, Al Ain, UAE

Picture of Mustak Dukandar

Mustak Dukandar

Tawam Hospital Emergency Department

Listen to the chapter

References

  1. Roberts and Hedges’ Clinical Procedures in Emergency Medicine and Acute Car-Elsevier (2017), chapter 25
  2. ATLS Student course manual Tenth Edition (2018). Appendix G, 351
  3. Phillips L, Brown L, Campbell T, et al. Recommendations for the use of intraosseous vascular access for emergent and nonemergent situations in various healthcare settings: a consensus paper. J Emerg Nurs. 2010;36(6):551-556. doi:10.1016/j.jen.2010.09.001
  4. Oksan D, Ayfer K. Powered intraosseous device (EZ-IO) for critically ill patients. Indian Pediatr. 2013;50(7):689-691. doi:10.1007/s13312-013-0192-z
  5. Leidel BA, Kirchhoff C, Bogner V, et al. Is the intraosseous access route fast and efficacious compared to conventional central venous catheterization in adult patients under resuscitation in the emergency department? A prospective observational pilot study. Patient Saf Surg. 2009;3(1):24. Published 2009 Oct 8. doi:10.1186/1754-9493-3-24
  6. Tallman CI, Darracq M, Young M. Analysis of intraosseous blood samples using an EPOC point of care analyzer during resuscitation. Am J Emerg Med. 2017;35(3):499-501. doi:10.1016/j.ajem.2016.12.005
  7. Wampler D, Schwartz D, Shumaker J, Bolleter S, Beckett R, Manifold C. Paramedics successfully perform humeral EZ-IO intraosseous access in adult out-of-hospital cardiac arrest patients. Am J Emerg Med. 2012;30(7):1095-1099. doi:10.1016/j.ajem.2011.07.010
  8. Day MW. Intraosseous devices for intravascular access in adult trauma patients. Crit Care Nurse. 2011;31(2):76-90. doi:10.4037/ccn2011615
  9. ACLS provider Manual Supplementary Material (2016). Intraosseous Access, 57-61
  10. Vidal R, Kissoon N, Gayle M. Compartment syndrome following intraosseous infusion. Pediatrics. 1993;91(6):1201-1202.
  11. Faga, M., & Wolfe, B. (2016). Vascular access in hospitalized patients. Hospital Medicine Clinics, 5(1), 1-16.
  12. Von Hoff, D.D., Kuhn, J.G., Burris, H.A. 3rd, & Miller, L.J. (2008). Does intraosseous equal intravenous? A pharmacokinetic study. Am J Emerg Med, 26, 31-38
  13. Miller LJ, Philbeck TE, Montez D, Spadaccini CJ. A new study of intraosseous blood for laboratory analysis. Arch Pathol Lab Med. 2010;134(9):1253-1260.

FOAM and Further Reading

Reviewed and Edited By

Picture of Arif Alper Cevik, MD, FEMAT, FIFEM

Arif Alper Cevik, MD, FEMAT, FIFEM

Prof Cevik is an Emergency Medicine academician at United Arab Emirates University, interested in international emergency medicine, emergency medicine education, medical education, point of care ultrasound and trauma. He is the founder and director of the International Emergency Medicine Education Project – iem-student.org, chair of the International Federation for Emergency Medicine (IFEM) core curriculum and education committee and board member of the Asian Society for Emergency Medicine and Emirati Board of Emergency Medicine.

Peripheral Intravenous Line Access and Blood Sampling (2024)

~ iEM Education Project Team ~ Leave a comment

by Omar F. Al- Nahhas, Mansoor M. Husain

Authors
Listen

Introduction

Peripheral IV Cannulation is a critical skill for healthcare providers in the Emergency Department, clinics, and the field. Knowing that it is one of the most essential procedures in the United States, where it is estimated that more than 25 million patients have peripheral intravenous (IV) catheters placed each year for vascular access for the administration of medications and fluids and the sampling of blood for analysis [1], makes it essential to master the technique, understand the subtleties of anatomy, and perform the procedure frequently to maintain this skill.

IV access plays a critical role in the emergency department as it permits the administration of medicines and fluids directly into the patient’s bloodstream, allowing prompt treatment of severe conditions such as dehydration, shock, and severe infections. The speed of treatment delivery is crucial in emergency scenarios, and peripheral IV access provides an efficient and effective way to deliver life-saving therapies. Additionally, it enables the frequent and easy sampling of blood, which is crucial for diagnosing and monitoring the patient’s condition. Therefore, healthcare providers in the emergency department must develop quick and reliable peripheral IV access skills to guarantee the best possible patient outcomes.

Indications

  • Administration of fluids: Patients who are dehydrated or unable to tolerate oral fluids may require IV fluids to maintain hydration and electrolyte balance [2].
  • Medication administration: Certain medications, such as antibiotics, chemotherapy drugs, and pain relievers, may need to be administered intravenously to achieve the desired effect.
  • Blood transfusions: Patients who have lost a significant amount of blood due to trauma or surgery may require a blood transfusion via an IV cannula.
  • Monitoring: IV access may be necessary for frequent blood draws or to monitor certain parameters, such as blood glucose levels.
  • Contrast material administration: Some imaging studies, such as CT scans, require the administration of contrast material via IV cannulas to help visualize certain structures.

Contraindications

There are no absolute contraindications. Relative contraindications include

  • Coagulopathy
  • The presence of local infection
  • Burns, or compromised skin at the intended site of insertion
  • Previous lymphatic nodal clearance, arteriovenous fistula formation, or deep venous thrombosis on the affected limb.

In such cases, clinical judgment must be used to balance the benefits and risks of proceeding with line placement at that site [2].

Equipment and Patient Preparation

Equipment

  • Gloves
  • Skin disinfectant (Povidine and Alcohol Swabs),
  • 16-18 gauge IV catheter (smaller catheters are better used in the pediatric population)
  • Tape
  • Syringe
  • 3-way stopcock
  • Tourniquet

Optional

  • Topical anesthetic, e.g., EMLA ( 2.5% lidocaine and prilocaine),
  • Transilluminator light
  • Ultrasound with a vascular probe.

Patient Preperation

To perform the procedure, obtaining consent from the patient after discussing the procedure and its associated risks and benefits is important. The preferred site for cannulation is the Cephalic vein in the forearm, followed by the Medial Brachial Vein in the Antecubital Sulcus.  The dorsum of the hand is also a common site, but this can be more painful for the patient, and often, smaller gauge cannulas are used. Always use universal precautions, such as wearing gloves, during the procedure. The selected vein should be visualized and palpated, as it will have a slight “give” compared to surrounding tissue.

The overlying skin should be disinfected, and a topical anesthetic may be applied as desired. While transillumination or ultrasound may provide additional guidance, care should be taken to avoid contamination of the clean, prepped site to be accessed.

Procedure Steps

The procedure for peripheral IV cannulation involves several steps [3]:

  1. Apply a tourniquet or blood pressure cuff inflated above the diastolic reading proximal to the intravenous site.
  2. Prepare the site with an antiseptic solution.
  3. Insert the IV catheter using a no-touch technique distal to and along the line of the vein at a 10 to 15-degree angle to the skin.
  4. Slowly advance the needle and catheter into the vein, waiting for a flash of blood to enter the catheter, which may not always occur.
  5. Slowly advance the needle an additional 1 to 2 millimeters and slide the cannula into the vein while securing the needle in place.
  6. Remove the needle while pressing on the overlying skin over the cannula proximal to the insertion site to stem the blood flow.
  7. Attach a 3-way stopcock and flush the stopcock and cannula with 5 ml of saline to prevent clotting. Assess the fluid flow through the catheter and watch for skin bulge, which may suggest fluid extravasation.
  8. Secure the catheter with tape or dressing and release the tourniquet or blood pressure cuff.
  9. Attach intravenous tubing to the 3-way stopcock, attach it to the fluid of choice, and initiate flow. Watch again for fluid extravasation. Medications may be administered through another port of the stopcock or added to the IV solution as desired.
  10. Ensure that the tourniquet is removed before administering drug or fluid infusion.
  11. If fluid extravasation occurs, remove the catheter and repeat the procedure at a more proximal site, avoiding distal attempts.
  12. These steps should be performed carefully and with appropriate attention to detail to ensure successful IV cannulation.

Blood Sampling

Blood sampling is a fundamental procedure in clinical practice for diagnostic and monitoring purposes. Various tubes are available for collecting blood samples, each designed for specific laboratory tests. For instance, the Vacutainer system offers a range of tubes with different additives to facilitate accurate test results. The choice of the tube depends on the required analyses, such as complete blood count (CBC), basic chemistry panels, coagulation studies, blood cultures, or specialized tests. Adhering to the appropriate tube selection based on the intended tests is crucial for obtaining reliable laboratory results. The amount of blood required for each tube varies depending on the specific test being conducted.

Generally, a CBC requires 2-4 mL of blood to obtain sufficient quantities of plasma or serum for cell counting and differential analysis [4]. Basic chemistry panels often necessitate larger volumes, ranging from 5-10 mL, to provide enough serum or plasma for multiple analytes, such as electrolytes, liver function tests, and renal function tests [4].On the other hand, blood culture bottles usually require 10 mL of blood to optimize the sensitivity of microbial detection [5]. Understanding the recommended blood volumes for each tube is crucial for ensuring adequate sample collection and accurate test results.

In summary, proper tube selection is essential for blood sampling to ensure accurate laboratory results. Various tubes with specific additives are available and tailored for different tests. The amount of blood needed for each tube varies depending on the type of analysis being conducted. Familiarity with the recommended blood volumes for each tube is crucial to obtaining sufficient sample quantities and optimizing diagnostic accuracy.

Complications

Despite the widespread use, IV cannulation is not without complications.

Phlebitis: This refers to vein inflammation, which can cause redness, warmth, and pain at the catheter site. The incidence of phlebitis ranges from 2% to 50% in adult patients and is related to various factors, including catheter gauge, insertion site, and duration of catheterization. [6]

Catheter-related bloodstream infections (CRBSIs): These are serious infections that can result from the colonization of the catheter by microorganisms. The incidence of CRBSIs is estimated to be 1-10% and is associated with prolonged catheterization, immunocompromised patients, and inadequate catheter site care.[7]

Infiltration and extravasation: Infiltration occurs when the fluid administered leaks into the surrounding tissue, while extravasation occurs when the medication or solution irritates the surrounding tissue, leading to tissue damage. The incidence of infiltration ranges from 4% to 38%, while extravasation occurs in less than 6% of patients. [8]

Hematoma: This is a collection of blood at the site of the catheter, which can occur due to trauma during catheter insertion or catheter displacement. Hematoma is reported in 0.5-8% of cases. [9]

Nerve injury: Nerve injury can occur due to direct trauma during catheter insertion, leading to motor and sensory deficits. The incidence of nerve injury is low, reported in less than 1% of cases. [10]

In conclusion, peripheral IV catheterization is a commonly performed procedure but not without complications. Careful attention to technique and site care can help minimize the risks of complications.

Hints and Pitfalls

To successfully perform peripheral IV cannulation, it’s important to use the correct technique and select an appropriate site with a visible vein.

  • Start by applying heat and a tourniquet to enhance blood flow, making the vein more prominent.
  • Once you have identified the vein, stabilize it and insert the cannula at an angle of 10 to 30 degrees, advancing it slowly while monitoring for proper placement.
  • Finally, secure the cannula using a transparent dressing or tape, ensuring it is not too tight.

Proper care and maintenance of peripheral intravenous (IV) lines are crucial to prevent complications and ensure patient safety. According to evidence-based guidelines, dressing care plays a vital role in IV line maintenance. Transparent semipermeable dressings are recommended by the Infusion Nurses Society (INS) as they provide a barrier against contamination and allow easy visualization of the insertion site [11]. Regular inspection of the dressing is important to identify any issues such as loosening, soiling, or moisture accumulation, and compromised dressings should be promptly replaced using sterile technique to reduce the risk of infection.

Flushing and locking peripheral IV lines are essential for maintaining patency. The INS recommends flushing with 0.9% sodium chloride (normal saline) solution before and after medication administration and at least every 8-12 hours for continuous infusions [11]. This practice helps prevent blood clot formation and ensures proper line functioning. When intermittent infusion is not expected for an extended period, the INS suggests using a saline or heparin lock to maintain line patency [11].

Vigilant monitoring and assessment of the peripheral IV site are critical to detect any signs of infection or complications. According to the Centers for Disease Control and Prevention (CDC), routine site inspection should be performed at least daily, paying close attention to redness, swelling, warmth, tenderness, or drainage [12]. Timely reporting and appropriate intervention in case of any abnormalities are crucial to prevent complications like phlebitis or infiltration.

Patient education is an essential aspect of peripheral IV line care. Educating patients and their caregivers about proper hand hygiene, signs of infection or complications, and when to seek medical assistance is vital. Patients should receive clear instructions to promptly report any pain, tenderness, or changes at the IV site.

It is important to note that specific institutional protocols may vary, and adherence to local guidelines is essential. These recommendations are based on current evidence and best practices in peripheral IV line care, aiming to promote patient safety and achieve optimal outcomes.

There are some pitfalls to avoid. Failure to use proper technique or choosing an inappropriate site can increase the risk of infection and complications such as infiltration, extravasation, or phlebitis. Applying too much heat or pressure with the tourniquet can cause burns or damage to the veins. Failure to stabilize the vein or inserting the cannula at the wrong angle can make cannulation more difficult or cause complications. Advancing the cannula too quickly or over-tightening the dressing can cause pain or discomfort, restrict blood flow, or damage the vein.

In time-critical cases with known difficult peripheral access or where multiple attempts at peripheral line placement have already failed, an ultrasound-guided technique may be necessary, or the clinician may consider using alternative routes of drug administration (such as oral, intramuscular, intraosseous, or central venous access).

Special Patient Groups

Certain populations, including pediatric, geriatric, and pregnant patients, require special considerations during peripheral IV catheterization.

Pediatrics

Pediatric patients have unique anatomical and physiological differences that affect the success of IV catheterization. The smaller size of their veins and thinner skin can make it challenging to locate and access suitable sites for catheter insertion [13]. 

Additionally, children have a higher risk of experiencing pain, discomfort, and anxiety during the procedure, which can lead to complications such as vasovagal syncope and catheter dislodgement. Therefore, healthcare providers need to use appropriate-sized catheters and consider non-pharmacological interventions, such as distraction techniques and topical anesthetics, to minimize the pain and discomfort associated with the procedure [13].

Geriatrics

Geriatric patients also require special consideration during peripheral IV catheterization. As individuals age, their veins become less elastic and more fragile, making it challenging to cannulate veins and increasing the risk of complications such as hematoma, infiltration, and extravasation. Furthermore, geriatric patients often have multiple comorbidities and take multiple medications, which can increase the risk of adverse reactions and interactions with IV medications. Therefore, healthcare providers must assess the patient’s venous status and consider alternative routes of medication administration when appropriate [14].

Pregnant Patients

Pregnant patients pose unique challenges during peripheral IV catheterization due to the physiological changes that occur during pregnancy. Increased blood volume, decreased venous compliance, and increased peripheral resistance make locating and accessing suitable veins for catheter insertion difficult. Additionally, certain medications and fluids can affect the mother and fetus, requiring careful consideration of the medication’s safety and potential risks. Therefore, healthcare providers can use ultrasound guidance and consider the patient’s gestational age, medical history, and current medications when selecting the site and medication for IV catheterization [15].

In summary, peripheral IV catheterization requires special considerations in pediatric, geriatric, and pregnant patients. Healthcare providers should assess the patient’s anatomical and physiological status and select appropriate-sized catheters. They should also consider non-pharmacological interventions to reduce pain and discomfort and carefully select the site and medication for IV catheterization to minimize the risk of complications.

Authors

Picture of Omar F. Al- Nahhas

Omar F. Al- Nahhas

Dr. Omar Al-Nahhas is a Senior Emergency Medicine Resident at STMC, Al-Ain, UAE, and an MSc Candidate in Medical Education at the University of Warwick. He is an Adjunct Clinical and Simulation Tutor at Ajman University and a certified BLS and ACLS Instructor. With publications in emergency medicine, his interests include Trauma, Sports Medicine, Critical care and Advanced Emergency Medicine, emphasizing education, research, and resuscitation practices.

Picture of Mansoor M. Husain

Mansoor M. Husain

Consultant Emergency Medicine, Tawam Hospital – Alain

Listen to the chapter

References

  1. Chopra V, Anand S, Hickner A, Buist M, Rogers MA, Saint S, Flanders SA. “Risk of venous thromboembolism associated with peripherally inserted central catheters: a systematic review and meta-analysis.” Lancet. 2013 Jul 27;382(9889):311-25. doi: 10.1016/S0140-6736(13)60592-9. Epub 2013 May 30. PMID: 23726390.
  2. Beecham GB, Tackling G. Peripheral Line Placement. [Updated 2022 Jul 25]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK539795/
  3. Keith A. “Intravenous (IV) Line Access” (n.d.). International Emergency Medicine Education Project, Available athttps://iem-student.org/intravenous-iv-line-access/.
  4. Clinical and Laboratory Standards Institute (CLSI). (2017). Procedures for the Collection of Diagnostic Blood Specimens by Venipuncture; Approved Standard—Eighth Edition. CLSI Document GP41-A8. CLSI.
  5. Clinical and Laboratory Standards Institute (CLSI). (2020). Principles and Procedures for Blood Cultures; Approved Guideline—Third Edition. CLSI Document M47-A3. CLSI.
  6. Helm RE, Klausner JD, Klemperer JD, et al. Accepted but unacceptable: peripheral IV catheter failure. J Infus Nurs. 2015;38(3):189-203.
  7. Blot SI, Depuydt P, Annemans L, et al. Clinical and economic outcomes in critically ill patients with nosocomial catheter-related bloodstream infections. Clin Infect Dis. 2005;41(11):1591-1598.
  8. Dougherty L, Lister S. Infusion Nursing: An Evidence-Based Approach. Elsevier Health Sciences; 2014.
  9. Feleke Y, Mekonnen N, Assefa A. Magnitude and associated factors of intravenous catheter-related hematoma in the adult emergency department of Tikur Anbessa Specialized Hospital, Addis Ababa, Ethiopia. BMC Emerg Med. 2018;18(1):10.
  10. Wallis MC, McGrail M, Webster J, et al. Risk factors for peripheral intravenous catheter failure: a multivariate analysis of data from a randomized controlled trial. Infect Control Hosp Epidemiol. 2014;35(1):63-68.
  11. Infusion Nurses Society. (2021). Infusion therapy standards of practice. Journal of Infusion Nursing, 44(1S), S1-S224.
  12. Centers for Disease Control and Prevention. (2021). Guidelines for the Prevention of Intravascular Catheter-Related Infections. Retrieved from https://www.cdc.gov/infectioncontrol/guidelines/bsi/index.html
  13. Naik VM, Mantha SSP, Rayani BK. Vascular access in children. Indian J Anaesth. 2019 Sep;63(9):737-745. doi: 10.4103/ija.IJA_489_19. PMID: 31571687; PMCID: PMC6761776.
  14. Gabriel, J. (2017). Understanding the challenges to vascular access in an ageing population. British Journal of Nursing, 26(14), S15–S23. doi:10.12968/bjon.2017.26.14.s
  15. Tan PC, Mackeen A, Khong SY, Omar SZ, Noor Azmi MA. Peripheral Intravenous Catheterisation in Obstetric Patients in the Hand or Forearm Vein: A Randomised Trial. Sci Rep. 2016 Mar 18;6:23223. doi: 10.1038/srep23223. PMID: 26987593; PMCID: PMC4796788.

Reviewed and Edited By

Picture of Arif Alper Cevik, MD, FEMAT, FIFEM

Arif Alper Cevik, MD, FEMAT, FIFEM

Prof Cevik is an Emergency Medicine academician at United Arab Emirates University, interested in international emergency medicine, emergency medicine education, medical education, point of care ultrasound and trauma. He is the founder and director of the International Emergency Medicine Education Project – iem-student.org, chair of the International Federation for Emergency Medicine (IFEM) core curriculum and education committee and board member of the Asian Society for Emergency Medicine and Emirati Board of Emergency Medicine.

Basics of Bleeding Control (2024)

~ iEM Education Project Team ~ Leave a comment

by Tasnim Ahmed & Abdulla Alhmoudi

Authors
Listen

Introduction

The primary objective in the resuscitation of traumatic hemorrhage is to achieve effective hemostasis and maintain hemodynamic stability. The severity of bleeding depends on the depth of the wound and the type of injured vessel. The approach to bleeding control should be tailored to the type and size of the bleeding vessel and the specific anatomical regions involved. Delayed or ineffective haemorrhage management can complicate the healing process and, in severe cases, lead to fatality. Extremity haemorrhage has historically contributed significantly to high mortality rates from casualties during wars [1]. Therefore, the prompt implementation of appropriate haemostatic techniques is a crucial aspect of efficient trauma management. This critical task is typically initiated by the prehospital team and followed by more advanced, invasive techniques provided by the trauma team in a controlled hospital setting

Types of Wounds

Wound is an impairment to the structural integrity of biological tissues, including the skin, mucous membranes, and organ tissues. This disruption in tissue integrity may arise from a diverse range of causes, including traumatic injuries, pathological processes, or surgical interventions. Metric parameters such as size (length), depth, shape, and whether they are open or closed are used to describe wounds.

The subsequent descriptors represent the terminology utilized for the classification of wounds:

Contusions

Contusions result from perpendicular blunt force to the skin, usually through a layer of clothes. Rupture of subcutaneous capillaries can occur, resulting in the formation of a hematoma (Figure 1). The recommended management for this type of wound consists of analgesics and following the “RICE” protocol (Rest, Ice, Compression, and Elevation) [2].

Figure 1 - Contusion

Abrasion

Abrasion is the scraping or scratching of the surface layers of skin (epidermis) when subjected to oblique forces (Figure 2). Proper wound care involves cleansing the wound, applying a sterile bandage, administering analgesics, ensuring tetanus protection, and implementing the RICE protocol [2].

Figure 2 - Abrasion

Incision

Incision is defined as a cut that features straight edges along the margins of the wound. It can be caused by sharp objects like scalpels, knives, sharp metal pieces, or glass (Figure 3). Tissue loss is uncommon, and the wound margins can be easily aligned for closure with medical glue or sutures [1,2,3].

Figure 3 - Incision

Lacerations

Characterized irregular or jagged edges, appearing torn rather than neat incisions [1,3]. They can have an irregular or linear direction and may branch out (Figure 4). Objects with broken or serrated edges or blunt impact on tissue overlying bone typically cause lacerations. Treatment approaches for lacerations are similar to those for incision wounds. However, the appropriate subspecialty should manage deep, complex lacerations or those involving sensitive areas like the face, joints, or tendons.

Figure 4 - Laceration

Avulsion

Avulsion involves a full-thickness laceration-type wound, which usually creates a flap of tissue (Figure 5) [1,3]. Mechanical accidents involving fingers (degloving injuries) can cause avulsions. More severe cases may include exposure of internal organs. Avulsions are challenging to repair and should never be considered minor injuries.

Figure 5 - Avulsion

Amputation

Amputations differ from avulsions in that they involve the complete loss of a limb, whereas avulsions result in the loss of just a flap of skin (Figure 6). It can occur at any point along an extremity and is usually accompanied by significant arterial bleeding. Despite the seriousness of this injury, a properly cooled and transported amputated limb may sometimes be surgically reattached in a hospital setting.

Figure 6 - Amputation

Puncture and Penetrating Wounds

Puncture and penetrating wounds result from the penetration of a sharp object into the tissue without lateral movement from the point of entry (Figure 7). Puncture wounds can be deceptive, as they may appear small on the surface but extend deeply, potentially damaging the neurovascular structure or internal organs and causing significant internal bleeding or secondary injuries. 

Figure 7 - Puncture wound with soft tissue infection

Stab wounds from knives or sharp objects, as well as bullet wounds, are examples of penetrating injuries [1,2,3]. Occasionally, the penetrating object may remain logged to the injury and should never be removed without careful assessment by the trauma team, as it might act as mechanical hemostatic and result in further bleeding once removed. 

Site of Injury

Injuries can also be classified into three types, depending on the injured site of the body; each entails a different approach to management. Extremity injuries refer to damage inflicted on the blood vessels of the arms or legs. Junctional injuries, on the other hand, involve vascular damage occurring at the junction where the extremities meet the torso, such as the hip, axilla, or base of the neck. Torso injuries often involve non-compressible truncal hemorrhage that occurs anywhere on the torso and involves large blood vessels.

Vascular Injury

Injury to any blood vessel type can result in external bleeding. The specific type of vascular injury can be identified based on the characteristics of bleeding observed [1,2,4].

The following are the distinct types of vascular injuries and their corresponding patterns of bleeding:

Arterial Bleeding

Arterial bleeding typically occurs as a consequence of deep penetrating injuries or amputations. It is distinguished by the forceful ejection of bright red blood from the wound synchronized with each heartbeat [2]. Complete laceration of the artery may trigger spontaneous constriction, which helps to control bleeding. However, if only the artery wall is damaged without complete dissection, it can lead to persistent bleeding.

Indicators of arterial injury are classified into hard signs and soft signs [2]. Identifying hard signs indicates an immediate need for arterial exploration and surgical intervention. To aid in the recollection of these hard signs, the mnemonic “The Broken PIPE” can be employed (Box 1). Conversely, soft signs indicate the necessity for additional investigations such as ankle-brachial index measurement, Duplex Doppler ultrasound, or CT angiography, as determined by clinical assessment. The soft signs can be represented by the mnemonic “NON-Deadly HemorrHage” (Box 2).

Venous Bleeding

Venous Bleeding is characterized by a slower flow of dark red blood out of the wound [2]. However, caution is still recommended in venous bleeding, as it can contribute to significant and rapid bleeding if left untreated [4].

Capillary Bleeding

Capillary Bleeding usually results from damage to subcutaneous capillaries. It is characterized by slow, intermittent bleeding in the form of dots or small oozing [2,4].

Indications of Bleeding Control Techniques

Achieving hemodynamic stability necessitates the effective control of all life- or limb-threatening bleeding. While in most cases of traumatic and non-traumatic resuscitation, emphasis is placed on managing the airway and ensuring proper breathing, in situations of exsanguinating bleeding, prioritizing massive hemorrhage control surpasses the immediate focus on airway and breathing management [1]. The choice of hemostatic technique should be based on the depth and specific location of the injury, as outlined in detail in the “Bleeding Control Techniques” section below.

Contraindications of Bleeding Control Techniques

There are no absolute contraindications to any specific hemostatic method [1]. However, bleeding injuries should not distract the physician from managing concurrent immediate life-threatening conditions. Additionally, immediate wound closure is not recommended in wounds older than 8 hours. Instead, these types of wounds should be cleaned thoroughly, covered with sterile dressing, and closed after 3-5 days if there are no signs of infection. This is referred to as “delayed primary closure” [2,3].

Preparation

Similar to all medical procedures, thorough preparation is essential to ensure efficient hemostasis. This preparation encompasses the healthcare team, equipment, medications, the patient, and the wound.

Team Preparation

The healthcare providers involved in the procedure should possess comprehensive knowledge of indications, contraindications, techniques, and potential complications. The team should wear appropriate personal protective equipment, including face masks, face shields, surgical gowns, gloves, and shoe covers as necessary [3]. This protective gear is crucial to safeguard against blood splashes and potential contact with body fluids, particularly in trauma settings where the patient’s health status may be unknown.

Equipment Preparation

The equipment and medications used for hemostasis must be meticulously prepared and checked for the expiry date and functionality. The required equipment is listed under the corresponding techniques in the “Bleeding Control Techniques” section below.

Patient Preparation

A detailed explanation of the procedure should be provided to the patient, and informed consent should be obtained if applicable. Additionally, securing intravenous access and collecting a blood sample for type and cross-matching and coagulation profile are imperative. Administering analgesics and local anesthetics before procedural maneuvers helps to effectively minimize patient discomfort and disruptive movements.

Wound Preparation

A thorough assessment of the wound should be conducted. Distal movement and neurovascular function should be assessed prior to any manipulation. Contaminated wounds require proper irrigation to remove foreign bodies, followed by sterilization of the surrounding skin using antiseptic solution such as povidone iodine or chlorhexidine. However, wound preparation should not delay definitive hemostatic measures [1,3]. 

Bleeding Control Techniques

Direct Pressure

The initial step in controlling bleeding involves applying direct pressure to the bleeding wound. This facilitates the formation of a platelet plug and the initiation of the physiologic coagulation cascade, which is typically achievable within 10 to 15 minutes of proper pressure application [1]. 

Equipment

  • Sterile gauze pad size 4×4
  • Compression bandage
  • Splint\brace

Technique

Ensuring the proper replacement of skin flaps is essential, followed by placing multiple 4×4 sterile gauzes, ideally low adherent type, with equal pressure applied. The wound can be wrapped with a compression bandage if it is in the head or extremities. Following the application of a compression bandage to the extremities, distal mobility, sensation, and perfusion should be checked. Limbs should be placed in a brace to minimize movement and keep it elevated. In body junctions, the wound can alternatively be packed with gauze or hemostatic agents along with topical pressure application [1,2,4].

Precautions

It is important to avoid removing soaked gauze, as this can function as a foreign clot; instead, a new gauze should be applied on top of the existing ones [4]. Compression bandages should be avoided in thoracic wounds, as they can constrict breathing.

Pressure on Arteries

When the source of bleeding cannot be identified, applying proximal pressure can help control the bleeding by reducing blood flow to the injured artery [1].  This is only feasible with extremity wounds and should not be applied to the carotid artery, as this can precipitate ischemic brain insult or vagal stimulation, resulting in bradycardia [4].

Precautions

The time of application is limited to 10 minutes due to the risk of tissue necrosis distal to the pressure point.

Tourniquet

The indication to use tourniquets is severe extremity bleeding that is not controlled by direct pressure application. The concept is constricting arterial flow to the injured area. It is an extremely painful procedure, and proper analgesia should be ensured before applying a tourniquet if time allows.

Equipment

  • Proper size tourniquet
  • Alternative: Blood pressure cuff

Technique

Remove any clothing obstructing the tourniquet application site, ensuring it is directly applied to the skin and remains visible. Position the tourniquet approximately 2-3 inches above the wound, avoiding joints (Figure 8). Tighten the tourniquet until the bleeding stops and the pulse distal to the tourniquet is no longer palpable. Note the time of placement on the tourniquet tag or consider using an indelible marker to write it on patient’s skin. [4,5].

Figure 8 - Tourniquet application

If bleeding is not controlled and the distal pulse is still present after applying the first tourniquet, apply a second one just above its location [4]. Increasing the width of the second tourniquet is more effective in controlling bleeding and reducing complications than excessively tightening the initial one. Administer analgesia as needed after the tourniquet is applied.

An alternative to the tourniquet is applying a blood pressure cuff proximal to the wound. The cuff is then inflated 20-30 mm Hg above systolic blood pressure or over 250 mm Hg, and the tubing is clamped with a hemostat [2]. There are many ways to improvise a tourniquet using non-stretchable clothing and a windlass rod like a pen; however, a commercially designed tourniquet is preferable and not likely to loosen easily with patient movement. 

To safely remove the tourniquet, apply a pressure dressing directly onto the wound. Then, gradually release the tourniquet while carefully monitoring for any signs of bleeding. If bleeding is successfully controlled, keep the tourniquet loosely secured in case of potential re-bleeding. If bleeding recurs, reapply firm pressure by tightening the tourniquet [5].

Precautions

The maximum duration for tourniquet application is 120 minutes [2]. Prolonged tourniquet application can lead to complications such as nerve injury, tissue necrosis, compartment syndrome, and rhabdomyolysis. However, if the extremity is amputated or if the tourniquet has been applied for more than 6 hours, it should not be loosened as permanent muscle damage occurs after 6 hours and might require amputation.1 Moreover, potential reperfusion injury may occur after 60 minutes of tourniquet use, leading to inflammation-induced damage in local areas and systemic effects on vital organs caused by inflammatory mediators [5].

Topical Hemostatic Agents

Another alternative or adjunct to tourniquet use is topical hemostatic agents. These agents create a platform for platelet deposition and facilitate hemostasis [6]. Examples include [1] oxidized cellulose (e.g., Surgicel), dry gelatin (e.g., Gelfoam, Surgifoam), or cyanoacrylate.

Equipment

  • Hemostatic agent (e.g., Combat Gauze, Celox Gauze, or ChitoGauze)
  • Pressure dressing

Technique

The hemostatic gauze is applied with direct pressure for at least 3 minutes. After the field dries, the wound can be sutured, or pressure dressing can be applied. It is important to note that a dry field is required to apply the cyanoacrylate type. Pressure or tourniquet should be used before its application. An alternative to hemostatic gauze is topical thrombin. It can be used directly or diluted with saline and sprayed onto the wound. A concentration of 100 units/mL is effective. In severe bleeding, a concentration of 1000 to 2000 units/mL can be used [1].

Precautions

Potential complications associated with hemostatic agents include excessive granulation tissue and fibrosis with absorbable gelatin agents or foreign body reaction with cellulose [1,7].

Balloon Catheter

Balloon catheters can be used as an improvised tamponade technique to temporarily control severe bleeding from deep injuries, when other conventional methods fail [1,8].

Equipment

  • Fogarty catheters, Foley catheters, or Sengstaken-Blakemore tubes.
  • 10 cc syringe

Technique

The tube is blindly inserted into the wound, then the ballon is inflated to halt bleeding from deep vascular injuries [1].

Suture Ligation

Suture ligation is used for controlling large bleeding vessels. An effective ligation technique requires careful examination and knowledge of the vascular anatomy to trace and identify the sources of bleeding. A retracted artery can be a potential source of delayed bleeding. Therefore, once an injured vessel is identified, the opposite end should also be traced and ligated [1]. 

Equipment

  • Blood pressure cuff
  • Absorbable suture (e.g., Vicryl, Monocryl, and PDS).
  • Haemostat
  • Needle holder
  • Scissors

Technique

A blood pressure cuff is placed proximally and inflated until the bleeding stops to create a clear field. With gradual deflation of the cuff, large bleeding vessels will start to be visible. Ligation is then completed with suturing in the following steps: [1]

  1. Using a haemostat pinch the free end of the bleeding vessel.
  2. Wrap a proper-sized suture around the vessel.
  3. Tie the suture at the base of the vessel.
  4. Release the haemostat carefully (Figure 9).

if the vessel can not be seen, a figure 8 suture can be applied (Figure 10) [1,3]. 

Figure 9 - Vessel ligation technique. (1) Grasp the cut end of the bleeding vessel with a haemostat. (2) Pass an appropriately sized suture around the vessel. (3) Tie and secure the suture around the base of the bleeding vessel. (4) Gently release the haemostat from the blood vessel. (Freeman C, Reichman EF. Hemorrhage Control. In: Emergency Medicine Procedures. 6th ed. Elsevier; 2020:112-1. "Control of the Bleeding Vessel that is Visualized." Adapted and redrawn by Tasnim Ahmed, MD).
Figure 10. Figure 8 stich. A. Needle directions, B.Tie. (Freeman C, Reichman EF. Hemorrhage Control. In: Emergency Medicine Procedures. 6th ed. Elsevier; 2020:112-2. "Control of a Bleeding Vessel Deep or Embedded in Tissue." Adapted and redrawn by Tasnim Ahmed, MD).

Cauterization

Cauterization is cost effective and simple haemostatic technique for small vessels measuring less than 2 mm in diameter. Electrical cauterization  involves using electrical current to heat an electrode, which then is used to thermally burn the vessel wall and seal it with charred tissue [1,10]. 

Chemical cauterization can be achieved using silver nitrate (AgNO3). This involves applying the agent to the vessel wall using an applicator, typically a long and small wooden stick tipped with the silver nitrate. Silver nitrate reacts with proteins in the tissue, forming an insoluble deposit that blocks the blood flow. It is only effective when applied to a dry tissue or minimal oozing [1]. 

Equipment

  • Blood pressure cuff
  • Silver nitrate or electric cautery

Technique

Position a blood pressure cuff proximally and gradually inflate it until bleeding stops, to achieve a clear field. Then gently release the pressure, until the smaller bleeding vessels become visible. Use the electrocautery to burn the end of the bleeding vessel or rub the silver nitrate against it to achieve an artificial clot [1].

Vasoconstrictors

In normal conditions, small vessels spontaneously stop bleeding. However, if bleeding persists, local vasoconstrictors mixed with local anaesthetics can be applied. Local anesthetic solutions containing epinephrine, such as lidocaine and bupivacaine, are readily available in the Emergency Department.

Equipment

  • 10 cc syringe
  • Epinephrine 1:1000
  • Saline-soaked gauze

Technique

Prepare the diluted epinephrine in a 10 cc syringe. Aspirate prior to injection to ensure that the solution is not injected into a blood vessel. Inject 1 to 2 mL of the solution around the bleeding vessel. Apply direct pressure with saline soaked gauze over the wound. Alternatively, spray the wound with the diluted solution. [1,3]

Precautions

It’s important to avoid using epinephrine or other vasoconstrictors in end-arterial areas like fingers, toes, ears, nose, or penis, to avoid organ ischemia.

Complications

Complications arise when the above-listed techniques are either overused or applied inappropriately. For detailed information regarding the particular complications associated with each technique, please refer to the corresponding technique’s “Precautions” section.  

Special Patient Groups

Obtaining hemostasis might be challenging in patients with coagulopathy. Therefore, it is important to remain vigilant and promptly assess the platelet count and plasma coagulation profile (PT/PTT/INR) in patients experiencing external bleeding. The early administration of tranexamic acid, blood products, and cryoprecipitate can aid in achieving hemostasis.

Authors

Picture of Tasnim Ahmed

Tasnim Ahmed

Emergency Medicine Residency graduate from Zayed Military Hospital, Abu Dhabi, UAE. Deputy Editor-in-Chief of the Emirates Society of Emergency Medicine (ESEM) newsletter. Senior Board Member and Website Manager of the Emirates Collaboration of Residents in Emergency Medicine (ECREM). Awarded Resident of the Year twice, at ESEM23 and Menatox23. Passionate about medical education, with a focus on blending art and technology into innovative teaching strategies.

Picture of Abdulla Alhmoudi

Abdulla Alhmoudi

Dr Abdulla Alhmoudi is a Consultant Emergency Medicine, serving at Zayed Military Hospital and Sheikh Shakhbout Medical City - Abu Dhabi. He pursued his residency training in Emergency Medicine at George Washington University in Washington DC and further enhanced his expertise with a Fellowship in Extreme Environmental Medicine. Dr Alhmoudi's passion for medical education is evident in his professional pursuits. He currently holds the position of Associate Program Director at ZMH EM program and is a lecturer at Khalifa University College of Medicine and Health Sciences. Beyond medical education, he maintains a keen interest in military medicine and wilderness medicine.

Listen to the chapter

References

  1. Chapter 112. Hemorrhage Control. In: Reichman EF. eds. Emergency Medicine Procedures, 2e. McGraw Hill; 2013. Accessed May 22, 2023. https://accessemergencymedicine.mhmedical.com/content.aspx?bookid=683&sectionid=45343754
  2. Spehonja A, Prosen G. Basics of Bleeding Control. In: Cevik AA, ed. International Emergency Medicine Education Project. iEM Education Project; 2018:598-601.
  3. Lammers RL, Smith ZE. Principles of wound management. In: Roberts JR, Hedges JR, eds. Roberts & Hedges’ Clinical Procedures in Emergency Medicine. 6th ed. Philadelphia, PA: Elsevier; 2014:611-634.
  4. Department of the Navy. Bleeding. Brooksidepress.org. 2001. Accessed May 22, 2023. https://www.brooksidepress.org/Products/OperationalMedicine/DATA/operationalmed/Manuals/Standard1stAid/chapter3.html.
  5. Lee C, Porter KM, Hodgetts TJ. Tourniquet use in the civilian prehospital setting. Emergency Medicine Journal. 2007;24(8):584-587. doi:10.1136/emj.2007.046359
  6. Sileshi B, Achneck HE, Lawson JH. Management of surgical hemostasis: topical agents [published correction appears in Vascular. 2009 May-Jun;17(3):181]. Vascular. 2008;16 Suppl 1:S22-S28.
  7. Levy JH. Hemostatic agents and their safety. J Cardiothorac Vasc Anesth. 1999;13(4 Suppl 1):6-37.
  8. Feliciano DV, Burch JM, Mattox KL, Bitondo CG, Fields G. Balloon catheter tamponade in cardiovascular wounds. Am J Surg. 1990;160(6):583-587. doi:10.1016/s0002-9610(05)80750-0
  9. Rudge WB, Rudge BC, Rudge CJ. A useful technique for the control of bleeding following peripheral vascular injury. Ann R Coll Surg Engl. 2010;92(1):77-78. doi:10.1308/rcsann.2010.92.1.77
  10. Kamat AA, Kramer P, Soisson AP. Superiority of electrocautery over the suture method for achieving cervical cone bed hemostasis. Obstet Gynecol. 2003;102(4):726-730. doi:10.1016/s0029-7844(03)00622-7

Reviewed and Edited By

Picture of Arif Alper Cevik, MD, FEMAT, FIFEM

Arif Alper Cevik, MD, FEMAT, FIFEM

Prof Cevik is an Emergency Medicine academician at United Arab Emirates University, interested in international emergency medicine, emergency medicine education, medical education, point of care ultrasound and trauma. He is the founder and director of the International Emergency Medicine Education Project – iem-student.org, chair of the International Federation for Emergency Medicine (IFEM) core curriculum and education committee and board member of the Asian Society for Emergency Medicine and Emirati Board of Emergency Medicine.

Cardiac Monitoring (2024)

~ iEM Education Project Team ~ Leave a comment

by Stacey Chamberlain

Authors
Listen

Definitions and Overview

Cardiac monitoring in the emergency setting is continuous monitoring of a patient’s cardiac activity in order to identify conditions that may require emergent intervention. These conditions include certain arrhythmias, ischemia and infarction, and abnormal findings that could signal impending decompensation. This chapter focuses specifically on cardiac monitoring or electrocardiography; additional methods of continuous hemodynamic monitoring in the emergency department (ED) include pulse oximetry, end-tidal CO2 monitoring, central venous pressure monitoring, and continuous arterial blood pressure monitoring. Of note, telemetry is the ability to do cardiac monitoring from a remote location; in practice, this is often a centralized system that might be located at a nursing station where multiple patients can be monitored remotely.

Cardiac monitoring differs from a 12-lead electrocardiogram in that it is done continuously over a period of time rather than capturing one moment in time in a static image. The benefit of this is that it captures transient arrhythmias and ectopic beats or monitors for changes over time. A disadvantage of cardiac monitoring is that typically, only 2 leads are displayed instead of a full 12 leads, giving a less comprehensive view of the heart and limiting its utility for looking for anatomic patterns. For example, on the 12-lead EKG, ED practitioners usually group the inferior, anterior, and lateral leads when looking for ischemic or infarct patterns. These may be less evident on a monitor with only two leads. Additionally, the static EKG allows the ED physician to carefully study it for subtle findings, for example, to make measurements of intervals, whereas in real-time monitoring, this is very difficult. In practice, both modalities are commonly used in conjunction for many ED patients.

The American Heart Association (AHA) published a consensus document in 2004 establishing practice standards for electrocardiographic monitoring in hospital settings, which was updated in 2017 [1,2]. These comprehensive documents outline the indications for cardiac monitoring, the specific skills required of the practitioner for cardiac monitoring, and specific ECG abnormalities that the practitioner should recognize. The 2017 update addressed the overuse of arrhythmia monitoring among certain populations, appropriate use of ischemia and QT-internal monitoring among select populations, alarm management, and documentation in electronic health records [2].

Cardiac monitoring is essential for those patients who are at risk for an acute, life-threatening arrhythmia and can also be used to evaluate for developing ischemia, response to therapy, and as a diagnostic tool. The AHA guidelines divide indications for cardiac monitoring in the inpatient setting into four classes based on varying degrees (level A, B, C) of evidence. Cardiac monitoring is considered indicated in patients in Class I. In Class IIa, it “is reasonable to perform” cardiac monitoring, whereas in Class IIb, it “may be considered.” For Class III, cardiac monitoring is not indicated as there is no benefit or there may actually be harm. Newer guidelines tailor the recommendations based on specific patient populations and whether the cardiac monitoring is for arrhythmia or continuous ST-segment ischemic monitoring [2]. Specific patient populations that are considered include patients with:

  1. Chest pain or coronary artery disease.
  2. Major cardiac interventions such as open heart surgery.
  3. Arrhythmias.
  4. Syncope of suspected cardiac origin.
  5. After electrophysiology procedures/ablations.
  6. After pacemaker or ICD implantation procedures.
  7. Pre-existing rhythm devices.
  8. Other cardiac conditions (acute decompensated heart failure or infective endocarditis).
  9. Non-cardiac conditions (e.g., post-conscious sedation or post-non-cardiac surgery).
  10. Specific medical conditions (e.g., stroke, imbalance of potassium or magnesium, drug overdose, or hemodialysis).
  11. DNR/DNI status.

Table 1 lists Class I-III recommendations. The AHA Scientific Statement provides a more comprehensive and detailed list.

Table 1 – Select Indications for Cardiac Monitoring

Class I Indications

Early phase ACS or after MI

 

After open-heart surgery or mechanical circulatory support

 

Atrial tachyarrhythmias

 

Symptomatic sinus bradycardia

 

2nd or 3rd degree AV block (exception as noted below for asymptomatic Wenckebach)

 

Congenital or genetic arrhythmic syndrome (e.g. WPW, Brugada, LQTS)

 

After stroke

 

With moderate to severe imbalance of potassium or magnesium

 

After drug overdose

Class IIa and IIb Indications

Non-sustained VT

 

Asymptomatic, significant bradycardia with negative chronotropic medications initiated

 

After non-cardiac major thoracic surgery

 

Chronic hemodialysis patients without other indications (e.g. hyperkalemia, arrhythmia)

Class III Indications

After non-urgent PCI without complications or after routine diagnostic coronary angiography

 

Patients with chronic atrial fibrillation, sinus bradycardia, or asymptomatic Wenckebach who are hemodynamically stable and admitted for other indications

 

Asymptomatic post-operative patients after non-cardiac surgery

 

DNR/DNI patients when the data will not be acted on and comfort-focused care is the goal

Ischemia Monitoring

Continuous ST-Segment Ischemia Monitoring was highlighted in the 2017 AHA guidelines as a specific indication for cardiac monitoring for patients most at risk for ischemia. Older monitors may not have this capability, but more modern monitors are programmed with automated ischemia monitoring that identifies abnormal ST-segment elevation or depression; manufacturers do not automatically enable this capability, and it may be turned on or off. To reduce unnecessary alarms, it is recommended (IIa level) to enable this function only in high-risk patients in the early phase of ACS and to individualize which lead should be prioritized based on the coronary artery suspected to be affected by an ischemic process. High-risk patients would include those being evaluated for vasospastic angina, those presenting with MI, post-MI patients without revascularization or with residual ischemic lesions, and newly diagnosed patients with a high-risk lesion such as a left main blockage.

QTc Monitoring

QTc monitoring aims to assess the safety of QT-prolonging medications and avoid Torsade de Pointes (TdP). Most hospitals do not have fully automated continuous QTc monitoring, so QTc monitoring and measurements may need to be performed manually or semi-automated with digital calipers. Regardless of the method, in general, recommendations for QTc monitoring are for patients with specific risk factors for TdP who are started on anti-arrhythmic drugs with a known risk for TdP (e.g., dofetilide, sotalol, procainamide, quinidine, and others), patients with a history of prolonged QTc started on non-anti-arrhythmic drugs with risk for TdP, those undergoing targeted temperature management, specific electrolyte derangements, and select drug overdoses. As with ischemic monitoring, QTc monitoring is not universally recommended for all patients, so consulting the 2017 guidelines for select patient scenarios is best.

Rhythm Interpretation

One of the most critical skills of an ED physician is in interpreting both static EKGs and interpreting arrhythmias on a cardiac monitor. A skilled practitioner must be able to diagnose common arrhythmias and be well-versed in the management of acute arrhythmias, recognizing which arrhythmias necessitate immediate action and which are less worrisome. Table 2 from the 2004 AHA guidelines lists the specific arrhythmias that the ED physician must be able to recognize. How and whether to treat an arrhythmia depends on many factors. The AHA has established algorithms for specific rhythms, including ventricular fibrillation (v-fib)/pulseless ventricular tachycardia (v-tach) and pulseless electrical activity (PEA)/asystole, as well as for non-specific rhythm categories such as bradycardia and tachycardia [3]. Additionally, they have published algorithms for clinical scenarios, including cardiac arrest, acute coronary syndrome, and suspected stroke.

The first step in the assessment of any rhythm is a clinical assessment of the patient. The premier issue of concern is if the patient is perfusing vital organs. A quick survey of the patient assessing mental status and pulses is essential to determining management. The management of a patient with v-tach will be substantially different if the patient is unresponsive and pulseless versus if the patient is awake with good pulses. As another example, the physician can quickly distinguish artifact from v-fib on the cardiac monitor by assessing the patient, as v-fib is not a perfusing rhythm.

The initial assessment of tachyarrhythmias (heart rate > 100) is to determine if the rhythm is “narrow-complex” (i.e., a QRS duration < 0.12s) or “wide-complex” (i.e., a QRS duration of 0.12s or greater). A narrow complex rhythm is considered a supraventricular rhythm (originating above the ventricles). Supraventricular tachycardia is a generic term encompassing any narrow-complex tachycardias originating above the AV node. Colloquially, when many practitioners refer to “SVT,” however, they are referring to a specific subcategory of supraventricular tachycardia called AV nodal re-entrant tachycardia (AVNRT). Wide complex tachycardias either originate in the ventricles or could originate in the atria and have an associated bundle branch block. Different criteria have been developed to help the practitioner distinguish between ventricular tachycardia and an SVT “with aberrancy” (i.e., aberrant conduction either due to an accessory path such as in Wolff-Parkinson-White or with a bundle branch block), the most well known of which are the Brugada criteria [4,5]. Practically speaking, many ED practitioners will assume the more dangerous and potentially unstable rhythm (v-tach) until proven otherwise; of course, the clinical picture and the patient’s vital signs are of utmost importance in determining the management of these patients. An excellent summary of this issue with rhythm strip examples is provided on the FOAM site “Life in the Fast Lane” [6].

Table 2 – Specific Arrythmias (adapted from AHA Scientific Statement [1])

Normal rhythms

 

 

Normal sinus rhythm

 

Sinus bradycardia

 

Sinus arrhythmia

 

Sinus tachycardia

Intraventricular conduction defects

 

 

Right and left bundle-branch block

 

Aberrant ventricular conduction

Bradyarrhythmias

 

 

Inappropriate sinus bradycardia

 

Sinus node pause or arrest

 

Non-conducted atrial premature beats

 

Junctional rhythm

AV blocks

 

 

1st degree

 

2nd degree Mobitz I (Wenckebach) or Mobitz II

 

3rd degree (complete heart block)

Asystole

 

Pulseless electrical activity (PEA)

 

Tachyarrhythmias

 

 

Supraventricular

Paroxysmal supraventricular tachycardia (AV nodal reentrant, AV reentrant)

Atrial fibrillation

Atrial flutter

Multifocal atrial tachycardia

Junctional ectopic tachycardia

Accelerated ventricular rhythm

Ventricular

Monomorphic and polymorphic ventricular tachycardia

Torsades de pointes

Ventricular fibrillation

Premature complexes

 

 

Supraventricular (atrial, junctional)

 

Ventricular

Pacemaker electrocardiography

 

 

Failure to sense

 

Failure to capture

 

Failure to pace

ECG abnormalities of acute myocardial ischemia

 

 

ST-segment elevation, depression

 

T-wave inversion

Muscle or other artifacts simulating arrhythmias

 

While each rhythm has distinctive management, it is worth noting for the novice learner that only v-fib and pulseless v-tach warrant asynchronized mechanical defibrillation (i.e. “shocking” the patient). Many students are stunned upon observing an asystolic cardiac arrest code to learn that shocking a “flatline” (i.e., asystolic) patient is an inappropriate treatment perpetuated by fictitious TV shows and movies. For unstable patients with arrhythmias but still have palpable pulses, synchronized cardioversion may be used.

Regarding medications, for certain rhythms and clinical scenarios, only vasopressor types of medications are used (e.g., epinephrine for asystole). For other rhythms and scenarios, antiarrhythmic medications are used (e.g., amiodarone for v-tach). Atrioventricular (AV) nodal blocking agents are often necessary for supraventricular tachyarrhythmias. One author suggests using a five “As” approach to treating emergency arrhythmias, keeping in mind the medications adenosine, amiodarone, adrenaline (epinephrine), atropine, and ajmaline [7]. Ajmaline is an antiarrhythmic that is not commonly used in English-speaking countries where procainamide is more common as an alternative to amiodarone for unstable v-tach.

Additional interventions may include pacemaker placement for symptomatic heart blocks. In many cases, the ED practitioner must also determine the underlying precipitant of the arrhythmia and tailor treatment to that cause. The emergency physician must familiarize himself with each rhythm and its unique management in any given clinical scenario.

At the end of this chapter, some good internet resources for the ED practitioner to practice interpreting EKGs and cardiac rhythms are provided.

Case Example

A 44-year-old male patient with a history of hypertension and end-stage renal disease on hemodialysis presents with shortness of breath after missing dialysis for 6 days. He reports gradual onset shortness of breath associated with orthopnea and increased lower extremity edema. He denies chest pain or palpitations. He does not have any cough or fever. On physical exam, he is in no distress, afebrile with a heart rate of 60, respiratory rate of 20, blood pressure of 140/78 mmHg, and oxygen saturation of 98% on room air. He has a regular rate and rhythm without murmurs and has crackles bilaterally to the inferior 1/3 of the lung bases and 1+ pitting edema of the bilateral lower extremities.

You decide to get an EKG, which shows the following:

Figure 1 (EKG from http://www.lifeinthefastlane.com)

You send a blood chemistry test, place the patient on a cardiac monitor, and one hour later note the following on the monitor:

Figure 2 - (EKG from liftl.com)

What are the indications for cardiac monitoring in this patient? What EKG abnormalities do you see? What does the rhythm strip show? What is the treatment?

Case Discussion

The ED practitioner should recognize potentially life-threatening conditions that a patient who has missed hemodialysis is at risk for are fluid overload (leading to pulmonary edema) and hyperkalemia. This patient could be considered to meet the Class I monitoring criteria for “needing intensive care” and possibly with “pulmonary edema”; however, even if the patient had no symptoms, the patient is indeed at risk for an acute life-threatening arrhythmia that would necessitate cardiac monitoring.

The EKG demonstrates peaked T waves indicative of acute hyperkalemia. Given the clinical picture of missed dialysis and the peaked Ts on the EKG, the ED physician should immediately initiate treatment for acute hyperkalemia without waiting for a confirmatory blood test (unless immediate point-of-care tests are available). If the patient’s hyperkalemia progressed, the patient could develop QRS widening with the morphology as shown on the rhythm strip called a “sine wave.” This dangerous finding could precipitously deteriorate into a life-threatening arrhythmia such as pulseless v-tach with cardiac arrest and should prompt immediate action. It is important to note that hyperkalemia can manifest in a variety of different EKG findings and does not always follow a consistent pattern from peaked Ts to QRS widening to sine waves; therefore, the patient should be treated at the first indication of any hyperkalemia-related EKG changes.

Conclusions

Cardiac monitoring is an important tool to monitor patients at risk for acute arrhythmias (including those at risk specifically for TdP) and acute or worsening cardiac ischemia. It can be helpful to immediately identify patients with life-threatening arrhythmias who need immediate intervention, to assess the response to medications for arrhythmias, and to help exclude arrhythmias as a likely etiology of a patient’s symptoms (e.g., a patient with syncope) [9]. Given the limited resources and the lack of benefits for many patients, the purpose and duration of cardiac monitoring should be carefully considered. Overuse can not only waste resources but can also contribute to alarm hazards, including “alarm fatigue,” where clinicians are barraged by so many false or nonactionable alarm signals that they become desensitized and do not respond to real events. Therefore, appropriate use and staff education are critical to maximizing the benefits of cardiac monitoring.

Author

Picture of Stacey Chamberlain

Stacey Chamberlain

Dr. Stacey Chamberlain is a board certified emergency physician who is a Professor in the Department of Emergency Medicine at the University of Illinois at Chicago (UIC). She also serves as the Director of the Global Emergency Medicine Fellowship Program and the Co-Director of the Social Emergency Medicine Fellowship Program. In addition to her work in Emergency Medicine, she is the Director of Academic Programs at the UIC Center for Global Health. In this role, she oversees the Global Medicine (GMED) Program for UIC medical students and the graduate global health certificate programs. Dr. Chamberlain has done clinical, educational, public-health, disaster-response, and emergency medicine development work, including working with several globally-focused NGOs, spanning five continents. Her global health work focuses on capacity building in emergency care in Uganda.

Listen to the chapter

2018 version of this topic – https://iem-student.org/cardiac-monitoring/

References

  1. Drew BJ, Califf RM, Funk M, Kaufman ES, Krucoff MW, et al. AHA Scientific Statement:  Practice Standards for Electrocardiographic Monitoring in Hospital Settings. Circulation. 2004; 110: 2721-2746. doi: 10.1161/01.CIR.0000145144.56673.59
  2. Sandau KE, Funk M, Auerbach A, Barsness GW, Blum K, Cvach M, Lampert R, May JL, McDaniel GM, Perez MV, Sendelbach S, Sommargren CE, Wang PJ; American Heart Association Council on Cardiovascular and Stroke Nursing; Council on Clinical Cardiology; and Council on Cardiovascular Disease in the Young. Update to Practice Standards for Electrocardiographic Monitoring in Hospital Settings: A Scientific Statement From the American Heart Association. Circulation. 2017 Nov 7;136(19):e273-e344. doi: 10.1161/CIR.0000000000000527. Epub 2017 Oct 3. PMID: 28974521.
  3. ACLS Training Center. Algorithms for Advanced Cardiac Life Support 2015. Dec 2, 2015.  Accessed at: https://www.acls.net/aclsalg.htm, Dec 10, 2015.
  4. Wellens HJJ. Ventricular tachycardia: diagnosis of broad QRS complex tachycardia. Heart2001;86:579-585 doi:10.1136/heart.86.5.579.
  5. Brugada P, Brugada J, Mont L, Smeets J, Andries EW. A new approach to the differential diagnosis of a regular tachycardia with a wide QRS complex. Circulation. 1991; 83: 1649-1659. doi: 10.1161/01.CIR.83.5.1649
  6. Burns E. VT versus SVT with aberrancy. Life in the Fast Lane. Accessed at: http://lifeinthefastlane.com/ecg-library/basics/vt_vs_svt/, Dec 10, 2015.
  7. Trappe H-J. Concept of the five ‘A’s for treating emergency arrhythmias. J Emerg Trauma Shock. 2010 Apr-Jun; 3(2): 129–136. doi:  10.4103/0974-2700.62111
  8. Ramzy M. Duration of Electrocardiographic Monitoring of Emergency Department Patients with Syncope. REBEL EM blog; June 13, 2019; Available at: https://rebelem.com/duration-of-electrocardiographic-monitoring-of-emergency-department-patients-with-syncope/.

Additional Online Resources

Reviewed and Edited By

Picture of Arif Alper Cevik, MD, FEMAT, FIFEM

Arif Alper Cevik, MD, FEMAT, FIFEM

Prof Cevik is an Emergency Medicine academician at United Arab Emirates University, interested in international emergency medicine, emergency medicine education, medical education, point of care ultrasound and trauma. He is the founder and director of the International Emergency Medicine Education Project – iem-student.org, vice-chair of the International Federation for Emergency Medicine (IFEM) core curriculum and education committee and board member of the Asian Society for Emergency Medicine and Emirati Board of Emergency Medicine.

Mechanical Ventilation (2024)

~ iEM Education Project Team ~ Leave a comment

by Elham Pishbin, Hamidreza Reihani

Authors
Listen

You have a new patient!

A 70-year-old male with a history of severe chronic obstructive pulmonary disease (COPD) presents to the emergency department (ED) with complaint of progressive dyspnea and productive cough. Vital signs are as follows: PR=108/min, RR=46/min, BP=130/90 mm Hg, T=37.8°C (axillary), SpO2=76% (with 5 L/min O2with nasal cannula). He is awake but confused. You request a blood gas test and initiate standard medical treatment for COPD exacerbation (Nebulized short-acting beta-agonists, antibiotics, and systemic glucocorticoids). You are concerned about the patient’s respiratory status and prepare for the possibility that he may need additional respiratory support in the emergency department.

Introduction

Mechanical ventilation (MV) is often essential to successfully managing critically ill patients. Patients may require MV because of respiratory failure, airway protection, or as part of the management of their illness to support their respiratory function and to reduce the work of breathing. Emergency physicians should have a solid understanding of mechanical ventilation and its indications, modes, and troubleshooting. Here, we provide a simplified guide to managing MV in the emergency department (ED) setting.

Physics of MV

MV involves pumping air with a positive pressure into the patient’s lungs and allowing the patient to exhale the air spontaneously.  The aim is to deliver oxygen to the lungs, keep the distal airways open for oxygen exchange, and allow carbon dioxide release upon exhalation. The ventilator uses pressurized air to overcome the resistance of ventilator tubing, the endotracheal tube (ETT), and airways. When the resistance to airflow increases or lung compliance decreases (lung compliance is inversely related to the elastic recoil of the lungs), higher pressure is required to inflate the lung [1, 2]. Common causes of high resistance are obstruction of the ETT by tube biting or a mucus plug, airway secretions, and bronchospasm. Common causes of poor compliance are pneumothorax, alveolar oedema, right main stem intubation, and air trapping [2].

Exhalation occurs passively due to pressure differences between the alveoli (higher pressure) and the ventilator (lower pressure). Notably, ventilators can administer a positive end-expiratory pressure (PEEP) to decrease this pressure gradient, thereby preventing the lungs from excessive collapse [2].

Control Variables and Ventilator Modes

The control variables on a ventilator determine how to pump the air (the air volume, the time over which the air is delivered, the frequency of delivering the air over a minute, and the speed at which the air travels). The alarms and monitors show whether the controls we set are appropriate and how the lungs respond [3]. 
After a patient is intubated and connected to a ventilator, the ventilator mode and settings should be established.  First, specify volume-controlled ventilation (VC) or pressure-controlled ventilation (PC) [1].

VC ventilation

VC ventilation is the most familiar and the most commonly used of MV modes in the ED [4].

The key parameters which should be set on the ventilator include [2]:

  1. Tidal volume (Vt): the amount of air pumped into the patient in each breath (measured in milliliters)
  2. Respiratory rate (RR)
  3. Fraction of inspired oxygen (FiO2)
  4. Positive end-expiratory pressure (PEEP): the baseline airway pressure at the end of expiratory. PEEP stents open the distal airways for gas exchange.
  5. Flow rate*: the speed at which Vt is pumped through the circuit (measured in liters per minute)
  6. Inspiratory time (Ti) *: the time (in seconds) over which the ventilator pumps the Vt

(*These parameters are often automatically set, but this depends on the ventilator)

In VC ventilation, pressure cannot be set as it depends on airway resistance and lung compliance. Increased airway resistance or worsened lung compliance will increase pressures in the airways, increasing the risk of barotrauma. Barotrauma due to elevated pressures is one disadvantage to VC. The advantage of VC ventilation is that the VT is guaranteed, and minute ventilation is stable.

PC ventilation

PC ventilation applies constant inspiratory pressure throughout inspiration, whether the ventilator or the patient triggers the breath [2]. In PC ventilation, the Vt cannot be set directly, so the operator sets the inspiratory pressure instead of Vt. Flow rate and Vt are dependent variables in PC ventilation. This is a disadvantage of PC ventilation since increased resistance or decreased compliance will lead to smaller Vt delivery, diminished ventilation, and carbon dioxide retention. Other key parameters, like Vt, PEEP, RR, and FiO2, are the same as VC ventilation. The advantage of PC ventilation is that airway and pulmonary pressures are set at the inspiratory pressures, preventing barotrauma. In addition, the patients can regulate their inspiratory flow rate and increase it according to their inspiratory efforts. This improves patient-ventilator synchrony [2].

A ventilator mode is a specific setting on the ventilator that determines how the ventilator assists the patient by giving a breath. It also defines the amount of respiratory support that the ventilator provides for the patient [5].

It is important to note that each ventilator mode has advantages and disadvantages.  There is no perfect ventilation mode that fits all patients. The best mode is the mode with which you and your team are most familiar [2].

Two primary ventilator modes that are most commonly used in the ED are Assist/Control Ventilation (ACV) Mode and Synchronous Intermittent Mandatory Ventilation (SIMV) Mode [4].

Assist/Control ventilation (ACV)

This mode is designed to offer full respiratory support for patients with minimal or no spontaneous breathing by delivering a preset number of mandatory breaths. However, if the patient tries to breathe, the ventilator will also assist that breath [5]. The patient will always receive at least the preset number of breaths (regardless of his/her respiratory effort). In this regard, ACV is the most appropriate initial mode in ED patients who are initially paralyzed and sedated [1].

ACV can be set as either volume-control or pressure-control. In VC/ACV, we set these parameters: Vt, flow rate, basal respiratory rate, and sensitivity to the patient’s respiratory effort (trigger). We can adjust the sensitivity control to make it easier or harder for the patient to trigger an assisted breath from the ventilator.
In PC/ACV, instead of Vt, we set the Ti.  In this mode, Vt is dependent on the patient’s lung compliance and airway pressure. The advantage is avoiding barotrauma, but the disadvantage is that a specific preset Vt cannot be guaranteed [4].

To ensure ventilator synchronization, a breath initiated by the patient takes precedence over a preset breath. If the ventilator is programmed to deliver 12 breaths per minute, it will provide a breath every five seconds in the absence of spontaneous breathing. However, if the patient makes a spontaneous effort, the ventilator will provide an extra breath and reset the timer for another five seconds. The main challenge is that patient-initiated breaths are not proportional to his effort. When the patient makes an inspiratory effort, the ventilator provides a full Vt, which can lead to hyperventilation and poor patient-ventilator synchronization. Adequate sedation is necessary to prevent spontaneous breathing efforts when a patient is ventilated in the ACV mode. [1].

Synchronous Intermittent Mandatory Ventilation (SIMV)

This mode offers intermittent ventilatory support to patients by delivering mandatory breaths and supporting spontaneous breaths. Mandatory breaths are delivered at a preset rate. The ventilator delivers at least a preset number of mandatory breaths to the patient, similar to ACV. Patients with no respiratory effort, will receive the preset number of breaths. Patients with spontaneous breathing at a lower rate than the ventilator preset rate will receive the preset number of breaths with full Vt. In these two scenarios, SIMV is very similar to ACV. However, if a patient has spontaneous breathing at a rate higher than the preset respiratory rate, additional respiratory effort beyond the preset rate will only be partially supported proportional to the patient’s respiratory effort. This makes SIMV an appropriate mode for less sedated patients with some degree of spontaneous breathing [1].

Pressure Support Ventilation (PSV)

In this mode, the ventilator assists the patient’s spontaneous breaths during the inspiratory phase of breathing. It is often used to help the patient overcome the airway resistance caused by the endotracheal tube and the ventilator circuit. The patient should be alert or on light sedation and able to follow commands. When the patient triggers a breath, the ventilator supports it by adding pressure to facilitate breathing. The operator sets the FiO2, PEEP, and inspiratory pressure on the ventilator based on how much support the patient needs to receive. In PSV, RR, Ti, and flow rate are determined by the patient. The higher the pressure support, the easier it will be for the patient to take a breath. The ventilator supports inspiration until the inspiratory flow falls below a preset measure [2,6].

When choosing PSV, it is also necessary to set an appropriate backup mode (for example, SIMV) and ventilator alarms [6].

Typical initial ventilator settings: Although required settings depend on whether PC or VC ventilation is selected, the principles are similar in both modes [1]. Typical initial ventilator settings include the following: [1,2,4]

  1. Tidal volume (Vt): a Vt of 6 to 8 mL/kg of estimated ideal body weight (IBW) is appropriate for most patients. The inspiratory pressure should be set in PC ventilation to achieve these Vt targets. Ongoing patient assessment is necessary to avoid excessive Vt. Regardless of VC or PC, initial pressure targets should not exceed 30 cm H2O.
  2. Respiratory rate: a rate of 12 to 18 breaths per minute would be reasonable for most patients and provide adequate ventilation. In special situations, such as patients with severe metabolic acidosis, the respiratory rate should be increased to match pre-intubation minute ventilation.
  3. FiO2: initially should be set at 100%, then lowered to target a SpO2 of 92% – 96% (PaO2 of 60 to 100 mmHg)
  4. PEEP: is routinely set initially at 5 cm H2O, but it can be set at 4 to 20 cm H2O
  5. I/E time ratio: The ratio of inspiratory time to expiratory time. It is commonly set as a ratio of 1:2. In some modes, it is automatically set based on other parameters. In some other modes, it needs to be set by the operator.
  6. Flow rate: is typically set at 60 L/min. (Vt will be delivered at the speed of 60 L/min). Increasing the flow rate will deliver the set Vt faster, reducing the inspiratory time. (It is found in VC modes)
  7. The trigger is a preset change in pressure or flow detected by the ventilator as the patient tries to initiate a breath, and the ventilator supports that breath. It should be set at a level that enables the patient to trigger the ventilator without great effort. For most patients, pressure sensitivity trigger from -0.5 to -2 cm H2O is effective and safe. The 1–3 L/min threshold is appropriate for the flow trigger setting.

When choosing a ventilator mode and parameters, it is essential to ensure adequate ventilation, but it is also important to ensure that the pressure in the ventilator circuit (including the lung) is appropriate [1]. Some important pressures are:

  • Peak inspiratory pressure (PIP) is the maximum pressure during inspiration. It is a dynamic pressure measured during the inspiration, so it incorporates airflow and reflects the resistance to airflow. It is also reflective of dynamic compliance of the entire respiratory system. Decreasing compliance or increasing resistance to airflow will increase PIP. It can never be lower than P. plat [4].
  • Plateau pressure (P. plat) is a static pressure that can be measured at the end of inspiration with a short breath-hold (Figure 1). The goal is to be less than 30 cm H2O. Decreasing the compliance will increase P. plat. Decreasing the Vt will decrease P. plat [4]
Figure.1: Airway pressure-time curve demonstrating PEEP, PIP, Pplat (Provided by the authors)
  • Positive End-Expiratory Pressure (PEEP) is the airway pressure at the end of expiration. It helps to keep the smaller airways and the alveoli open, prevents atelectasis, and improves oxygenation. Increased levels of PEEP may lead to lung injury. Additionally, high PEEP can depress cardiac output and lead to hemodynamic compromise [1,4]. When talking about PEEP, most authors mean extrinsic PEEP (PEEPe). In this chapter, when we use PEEP, we refer to PEEPe.
  • Intrinsic PEEP or auto-PEEP (PEEPi) results from air trapping in the airways. It occurs due to increased expiratory resistance (e.g., bronchospasm, kinked ETT), impaired elastic recoil (e.g., emphysema), and increased minute ventilation (inadequate expiratory time). PEEPi can lead to hemodynamic instability similar to high levels of PEEP [2,4].

Noninvasive ventilation (NIV)

NIV provides continuous positive pressure throughout the breathing cycle via a tight-fitting mask (nasal, oro-nasal, or full-face mask, as shown in Figure 2) rather than an endotracheal tube [7].

Figure.2: NIV masks: A, B: Oro-nasal mask, C: Nasal mask, D: Full face mask (provided by authors)

No mandatory breath is given by the ventilator so the patient must have spontaneous breathing. The ventilator provides a preset level of pressure when the patient initiates a breath, but inspiratory flow and Ti are completely patient-dependent [4,7]NIPPV can be delivered as continuous positive airway pressure (CPAP) or bi-level positive airway pressure (BiPAP).

CPAP provides constant positive pressure throughout the entire respiratory cycle. Its main effect is applying positive pressure at the end of expiration and exerts a minimal effect on inspiration [4,7].

BiPAP supplies a positive airway pressure during inspiration (IPAP) and a lower positive airway pressure during expiration (EPAP) [4].

IPAP provides pressure support and decreases the patient’s work of breathing. Increasing the IPAP will improve tidal volume and minute ventilation, thereby helping to eliminate CO2 from the alveoli.

EPAP acts similar to PEEP and improves alveolar recruitment and oxygenation by maintaining positive pressure at the end of expiration. EPAP prevents the lung from being fully deflated at the end of expiration, aiding in oxygen exchange across the alveolar-capillary membrane. Therefore, when you need to improve oxygenation, you should increase the EPAP.

The difference between the IPAP and EPAP is called delta pressure. The delta pressure is the same as pressure support in invasive ventilation. When the difference between the IPAP and EPAP is larger, the patient is able to have a larger tidal volume. Therefore, when you need to increase the clearance of CO2, you need to increase the delta pressure. [1,7].

Contraindications to NIV are patients who are uncooperative, hemodynamically unstable, lack protective airway reflexes, lack good respiratory effort, or have maxillofacial trauma. [7,8]

Initial NIV Settings

Initial settings depend on the amount of support that the patient requires, patient comfort, and patient cooperation.

BiPAP usually is initiated at 10 cm H2O for IPAP and 5 cm H2O for EPAP. Based on the patient’s clinical response, these parameters can be titrated later by 1 to 2 cm H2O at a time. However, the maximum pressure for IPAP should not exceed 20 cm H2O because this may lead to barotrauma [8,9].

Typical initiated settings for CPAP are 5 to 15 cm H2O [4,7].

Ventilator Troubleshooting

Patient-ventilator dys-synchrony refers to patients who develop respiratory distress after undergoing mechanical ventilation [10]. Emergency physicians must be familiar with patient-ventilator interactions so that life-threatening complications of mechanical ventilation can be promptly identified and managed [11]. In Figure 3, we present a systematic approach to detect life-threatening conditions in patients who suddenly deteriorate and become hemodynamically unstable (profound hypotension or cardiac arrest) under mechanical ventilation [1, 10].

Figure-3: Evaluation of respiratory distress in hemodynamically unstable mechanically ventilated patients (Provided by authors)

Revisiting Your Patient

After 30 minutes, you reevaluate your patient. The patient remains in respiratory distress with SpO2 of 79%, despite nebulized beta-agonists, steroids, antibiotics, and the use of 7 L/min O2 via face mask. The patient’s blood gas reveals a pH of 7.22, PCO2 of 80 mm Hg, and PaO2 of 55 mmHg. You decide to put him on NIV using an oro-nasal mask. You choose BiPAP mode and set IPAP=12 cm H2O, EPAP=7 cm H20, and FIO2= 90%.  After 5 minutes, the patient becomes agitated on the NIV mask, even with verbal direction and support. The pulse oximeter remains low at a SpO2 of 85%.

What would be the next appropriate step in the management of this patient?

You recognize your patient has not sufficiently improved despite maximal medical therapies. You decide to prepare for intubation and mechanical ventilation. The patient is fully sedated, paralyzed, and intubated using RSI (rapid sequence intubation). You prepare to choose a ventilation mode and set the parameters on your ventilator.

Which mode of ventilation and control parameters are most ideal for your patient?

The patient is sedated and paralyzed during RSI, so the VC/ACV mode is the best choice. Your senior says, “The best mode is the mode most familiar to you.”  No data suggest the advantage of PC over VC (or vice versa) in patients with COPD. You review your goals in MV of your COPD patient: improve oxygenation and ventilation, minimize PEEPi, and prevent barotrauma. 

You set the ventilator as:

  • Mode: ACV (VC/ACV)
  • FiO2= 100%
  • Vt= 500 cc
  • Respiratory rate= 14
  • PEEP= 5cm H2O
  • I/E: 1/4

You base your tidal volume on the patient’s 170 cm height and weight of 90 kg. You set the I/E ratio at 1:4 to optimize a longer expiratory time and titrate the FiO2 until the SpO2 falls between 88% to 92% [12]. A chest X-ray confirms the tip of the endotracheal tube is located above the carina.  The patient is admitted to the medical ICU for further management and treatment.

Authors

Picture of Elham Pishbin

Elham Pishbin

Elham Pishbin is a full-time associate professor of emergency medicine (EM) with 16 years of experience as a faculty member of the department of EM at Imam Reza Hospital, affiliated with Mashhad University of Medical Sciences, Mashhad, Iran. She is a member of the Iranian national board of EM and contributed to establishing the first EM residency program at Mashhad University of Medical Sciences in 2008, the fifth EM residency program in Iran, and a significant milestone in the development of EM in the country.

Picture of Hamidreza Reihani

Hamidreza Reihani

Dr. Hamidreza Reihani, a professor of emergency medicine at Mashhad University of Medical Sciences in Iran, is also a member of the national board of emergency medicine. He holds fellowships in medical education, research, and clinical informatics. With 15 years of experience in emergency medicine, he has made significant contributions, including founding an academic Emergency Department (ED) at his university and educating over 100 specialists in the field. Dr. Reihani has also been actively involved in interdisciplinary and undergraduate education, research (with more than 60 published articles), peer review, and editorial roles for two academic journals. His expertise and dedication are reflected in his contributions to both the previous and current editions of this book.

Listen to the chapter

References

  1. Seigel T.A, Johnson N.J. Mechanical ventilation and noninvasive ventilatory support. In: Walls R.M, ed. Rosen’s emergency medicine: concepts and clinical practice. 10th ed. Philadelphia PA: Elsevier; 2023:24-33
  2. Ward J, Noel C. Basic Modes of Mechanical Ventilation. Emerg. Med. Clin. N. Am. 2022;40(3):473-88
  3. Gomersall C, Joynt G, Cheng C, et al. Basic Assessment and Support in Intensive Care. Hong Kong: Chinese University of Hong Kong; 2013:37-54.
  4. Santanilla J.I. Mechanical Ventilation. In Roberts J.R, Hedges J.R, eds. Roberts and Hedges’ clinical procedures in emergency medicine and Acute Care. 7th ed. Philadelphia PA: Elsevier; 2018:152-172.
  5. Hickey S, Giwa A. Mechanical ventilation. StatPearls. 2023 Jan 26.
  6. Abramovitz A, Sung S. Pressure Support Ventilation. StatPearls. 2022. Sep 18.
  7. Gill HS, Marcolini EG. Noninvasive mechanical ventilation. Emerg. Med. Clin. N. Am. 2022;40(3):603-13.
  8. Carlson J.N, Wang H.E. Noninvasive Airway Management. In: Tintinalli J.E, ed. Tintinalli’s emergency medicine: a comprehensive study guide, 9th ed. McGraw Hill Education; 2020: 178-183.
  9. Baker DJ, Baker DJ. Basic Principles of Mechanical Ventilation. Artificial Ventilation: A Basic Clinical Guide. 2020:113-37.
  10. Keith RL, Pierson DJ. Complications of mechanical ventilation: a bedside approach. Clinics in chest medicine. 1996 Sep 1;17(3):439-51.
  11. Gilstrap D, MacIntyre N. Patient–ventilator interactions. Implications for clinical management. American journal of respiratory and critical care medicine. 2013 Nov 1;188(9):1058-68.
  12. Atchinson P.R, Roginski M.A. Chronic obstructive pulmonary disease. In: Walls R.M, ed. Rosen’s emergency medicine: concepts and clinical practice. 10th ed. Philadelphia PA: Elsevier; 2023:806-815

Free open access resources for study

Reviewed and Edited By

Picture of Joseph Ciano, DO, MPH, MS

Joseph Ciano, DO, MPH, MS

Dr. Ciano is a board-certified attending emergency medicine physician from New York, USA. He works in the Department of Emergency Medicine and Global Health at the Hospital of the University of Pennsylvania. Dr. Ciano’s global work focuses on capacity building and medical education and training in low-middle income countries. He is thrilled to collaborate with the iEM Education Project in creating free educational content for medical trainees and physicians.

Picture of Arif Alper Cevik, MD, FEMAT, FIFEM

Arif Alper Cevik, MD, FEMAT, FIFEM

Prof Cevik is an Emergency Medicine academician at United Arab Emirates University, interested in international emergency medicine, emergency medicine education, medical education, point of care ultrasound and trauma. He is the founder and director of the International Emergency Medicine Education Project – iem-student.org, chair of the International Federation for Emergency Medicine (IFEM) core curriculum and education committee and board member of the Asian Society for Emergency Medicine and Emirati Board of Emergency Medicine.

Emergency Procedures: Intraosseus Needle Insertion

emergency procedures-Intraosseus Insertion
~ iEM Education Project Team ~ Leave a comment

Indications

  • Emergency intravenous access is required and Peripheral intravenous access is difficult or has failed.

This video has been provided by Emergency Procedures App developers (Dr John Mackenzie and Dr James Miers) in order to help medical students, interns in training. Please visit the video source or Emergency Procedures app for more procedure videos and information. 

Contributors

Picture of Dr John Mackenzie

Dr John Mackenzie

Dr John Mackenzie MBChB , Dip MSM, FACEM . Staff Specialist Emergency Medicine, Consultant Hyperbaric Medicine Specialist, at Prince of Wales Hospital. Known for cycling endlessly for no apparent reason. 20 years of developing virtual learning for clinicians at all levels.

Picture of Dr James Miers

Dr James Miers

Dr James Miers BSc BMBS (Hons) FACEM, Staff Specialist in Emergency Medicine, Prince of Wales Hospital, Sydney. Passion for gypsy jazz and chess. Lead author of Lead author of Emergency Procedures App.

Further Reading

Emergency Procedures: Patella Relocation

emergency procedures-patella relocation
~ iEM Education Project Team ~ Leave a comment

Indications

  • Patella dislocation

This video has been provided by Emergency Procedures App developers (Dr John Mackenzie and Dr James Miers) in order to help medical students, interns in training. Please visit the video source or Emergency Procedures app for more procedure videos and information. 

Contributors

Picture of Dr John Mackenzie

Dr John Mackenzie

Dr John Mackenzie MBChB , Dip MSM, FACEM . Staff Specialist Emergency Medicine, Consultant Hyperbaric Medicine Specialist, at Prince of Wales Hospital. Known for cycling endlessly for no apparent reason. 20 years of developing virtual learning for clinicians at all levels.

Picture of Dr James Miers

Dr James Miers

Dr James Miers BSc BMBS (Hons) FACEM, Staff Specialist in Emergency Medicine, Prince of Wales Hospital, Sydney. Passion for gypsy jazz and chess. Lead author of Lead author of Emergency Procedures App.

Further Reading