Airway Procedures (2024)

December 26, 2024December 26, 2024 ~ iEM Education Project Team ~ Leave a comment

by Eirini Trachanatzi & Anastasia Spartinou

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.

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.

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.

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.

Procedure Steps

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.
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.

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]

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.
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.
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.

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.

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

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.
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:

Inability to maintain a patent airway and risk of aspiration (e.g., acutely decreased mental status or impending airway obstruction).
Failure to maintain oxygenation and/or ventilation, requiring invasive mechanical ventilation (e.g., severe exacerbations of asthma or COPD).
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).

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).

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.

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].

Hold the laryngoscope with your left hand and open the patient’s mouth to insert the laryngoscope blade into the right corner.
Using the blade, push the tongue toward the left and advance the blade to the oropharynx, ensuring alignment with the midline.
Visualize the epiglottis and lift it to reveal the vocal cords.
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.
Inflate the tube’s cuff to achieve an airtight seal of the airway.
Confirm the ETT’s placement with the use of capnography.
Auscultate to verify that the tube ventilates both lungs.
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].

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

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.

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.

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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.
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.
RSI setup checklist. Broome Docs – Rural Generalist Doctors Education. Accessed April 14, 2023. https://broomedocs.com/clinical-resources/rsi-setup-checklist/
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.
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.
Abdallah C. Pediatric endotracheal intubation. Middle East J Anesthesiol. 2015;23(1):123-124.
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.
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.
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.
Petersen A, Wong E, Brown T. Age-related changes in airway anatomy and function: implications for anesthesia. Anesthesiol Clin. 2018;36(1):1-12.
Hernandez A, Lee C, Patel K. Challenges in airway management in older adults. Anesth Analg. 2021;132(3):710-717.
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

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.

Bronchial Foreign Body Aspiration (2024)

December 3, 2024December 3, 2024 ~ iEM Education Project Team ~ Leave a comment

by Elhaitham Ahmed & Khalifa Alqaydi

You have a new patients!

Patient 1

A 72-year-old male was brought from an inpatient stroke rehabilitation center to the emergency department for a cough lasting the past ten days. Along with the cough, the patient was noted to have blood-tinged sputum, which is sometimes foul-smelling. His vital signs are as follows: temperature of 38.4°C, blood pressure of 138/78 mmHg, heart rate of 103 bpm, respiratory rate of 26 breaths/min, and oxygen saturation of 93% on room air. On physical examination, the patient exhibits tachypnea, dullness on percussion, bronchial breathing, egophony, and increased vocal fremitus upon examining the right side of his lung.

Patient 2

Thirty minutes later, the nurse calls you regarding a 5-year-old boy brought in by his mother, presenting with stridor and an ongoing cough. The mother mentions that she found her child playing with her wallet while she was in the next room and discovered him in this condition. The child is tachypneic, saturating at 90% on room air with subcostal retractions. Examination of the right lung revealed wheezing with decreased air entry.

What do you need to know?

Importance

Tracheobronchial foreign body aspiration (FBA) can be a potentially life-threatening event. FBA in children may be suspected based on a choking episode if such an episode is witnessed by an adult or remembered by the child. In contrast, the clinical presentation of unwitnessed FBA may be subtle, requiring careful review of the history, clinical assessment, and judicious use of radiography and bronchoscopy for diagnosis. Flexible and rigid bronchoscopy have become the cornerstone of both diagnosis and treatment in patients with suspected airway foreign bodies, which are most commonly seen in patients with FBA [1].

Epidemiology

FBA is more common in children than in adults. Data from the National Security Council report that approximately 80 percent of cases occur in patients younger than 15 years of age, with the remaining 20 percent presenting in those older than 15 years. Overall, death from FBA is the fourth leading cause of accidental home and community deaths in the United States, with over 5,000 fatal episodes of FBA reported during 2015. Death from FBA peaks in children under 1 year old and in adults over 75 years [2].

Pathophysiology

In children, nuts, seeds, and other organic material account for the majority of foreign bodies. However, in adults, the nature of inhaled objects is highly variable, ranging from organic to inorganic material. The type of foreign body significantly impacts the degree of tissue reaction in the airway. For example, some inorganic materials, such as metal or glass items, may cause little tissue inflammation but can result in direct airway injury if they are sharp. In contrast, some organic materials, such as nuts and a variety of pills, can cause significant inflammation, granulation tissue formation, and airway stenosis. Aspirated organic material can also expand from airway moisture, worsening obstruction. Aspiration of medications in pill form, such as iron tablets, aspirin, and potassium chloride, can also cause severe airway inflammation and ulceration [2].

Medical History

Clinical presentation can range from chronic nonspecific respiratory complaints to acute airway obstruction. In most cases of aspiration, the presence of a foreign body can be suspected after a thorough history. Patients with airway foreign bodies may present with noisy breathing, inspiratory stridor, rhonchi, vomiting, changes in voice, and hemoptysis [3]. Some patients may report a history known as penetration syndrome, which includes a choking sensation accompanied by wheezing and coughing. Coughing may not completely expel the foreign body but may instead cause its impaction in the subglottic region. Therefore, coughing after suspected aspiration should prompt a search for a foreign body, even if symptoms improve [4].

In pediatric patients with suspected foreign body aspiration, the sudden onset of choking or intractable cough associated with wheezing and respiratory distress occurs in more than 63% of cases [5,6]. In addition to coughing and choking, stridor is a frequent symptom. The absence of early coughing and choking is associated with delayed diagnosis and chronic presentations, such as recurrent pneumonia [4]. The sudden onset of dyspnea and odynophagia may indicate an impacted subglottic object. If the object is sharp and thin, the emergency clinician should suspect embedding between the vocal cords or in the subglottic region, resulting in partial obstruction [7].

Other components of the history can assist in diagnosing and characterizing foreign bodies in patients with aspiration of nonfood objects. Many types of items may be aspirated by children exploring their environment. Another at-risk population includes individuals who habitually store small items in their mouths for quick access; examples include construction workers (nails) and seamstresses (pins). The presentation of patients with a retained airway foreign object may involve only infectious complications. A foreign object can lead to a retropharyngeal abscess. Patients with atypical or recurrent pneumonia may have pulmonary infections caused by the persistence of a foreign object serving as a focus of infection [6].

Physical Examination

Physical findings depend on the degree of airway obstruction and the duration of the object’s presence. Depending on the size and location of the foreign body, the examination may reveal a normal patient, one with cyanosis and respiratory arrest, or any condition between these two extremes. Patients may exhibit stridor or hoarseness with upper airway foreign objects, and intercostal or sternal retractions may be observed in patients with high-grade obstruction caused by tracheal foreign bodies [8]. Hypoxemia may be present; however, normoxia does not rule out the presence of a foreign body. Patients with secondary infections may present with fever.

Oropharyngeal examination may reveal a foreign body posteriorly or donor sites of fractured teeth. The examination should also include a search for fractured or missing dental prostheses. Oropharyngeal examination can often be supplemented by indirect or direct laryngoscopy or nasopharyngoscopy, but these procedures should be performed only if the procedural stress does not pose an undue risk of airway compromise.

Coughing may result from local irritation caused by bronchial foreign bodies. Localized or apparently generalized wheezing is frequently auscultated in patients with lower respiratory tract foreign bodies [9]. Complete obstruction of a mainstem bronchus may result in absent ipsilateral breath sounds; however, breath sounds can sometimes be transmitted across the thorax, and the only physical abnormality may be asymmetric chest rise. Occasionally, a foreign body acts as a one-way valve, allowing air into the lung during inspiration but preventing its exit during expiration. The affected lung becomes hyperexpanded, which may be detected as hyper-resonance on percussion [6].

Alternative Diagnoses

The selected differential diagnoses for airway foreign bodies include anaphylactic reactions, acute pharyngitis, acute epiglottitis, retropharyngeal abscess, neck tumors, pulmonary carcinomas, pneumonia, bronchitis, bronchiolitis, and tuberculosis.

Acing Diagnostic Testing

Imaging should not delay intervention in cases of suspected acute asphyxiation but is indicated for stable patients [10].

Findings on imaging depend on the type and location of the material aspirated and the time elapsed. In practice, plain films of the neck and chest are often performed simultaneously and can be followed by site-specific CT if suspicion remains. The majority of foreign bodies are radiolucent and not easily identified on plain film. If obstruction of the upper airway (oropharynx and upper trachea) is suspected, initial imaging should include anterior-posterior and lateral soft tissue views of the neck [11]. If these tests are negative and suspicion for FBA persists, further imaging with CT may be indicated. When FBA of the lower airways (below the vocal cords) is suspected, a chest radiograph should be the initial radiographic test to look for an obvious radiopaque airway lesion. Negative scans may prompt further evaluation with CT. The reported sensitivity of chest radiography is approximately 60 to 80 percent in children, and clinical experience suggests similarly poor sensitivity in adults [12].

Given its widespread availability, flexible bronchoscopy is often the diagnostic procedure of choice for non-life-threatening FBA in adults, particularly in cases involving smaller foreign bodies in the lower airway. Flexible bronchoscopy allows precise identification and localization of foreign bodies and facilitates the selection of instruments necessary for retrieval [13]. Additionally, flexible bronchoscopy enables removal of the foreign body during the diagnostic procedure if the operator is skilled in these techniques. Standard diagnostic or therapeutic flexible bronchoscopes are usually adequate for the management of FBA in adults [6].

Risk Stratification

Risk factors in adults include loss of consciousness due to trauma, drug or alcohol intoxication, or anesthesia. Additional risk factors in older adults include age-related slowing of the swallowing mechanism, medication use (impairing cough and swallowing), stroke-related dysphagia, and various degenerative neurologic diseases such as Alzheimer’s or Parkinson’s disease [2].

Management

In a conscious adult, data support the efficacy of chest thrusts, back blows or slaps, blind finger sweeps, and abdominal thrusts in relieving complete foreign body airway obstruction [6, 14]. In cases of life-threatening asphyxiation, initial support should focus on treating airway obstruction and respiratory failure. Once the airway is secured, a laryngoscopic evaluation of the oropharynx should be performed immediately to diagnose and retrieve a supraglottic or glottic foreign body. If a foreign body is not seen, rigid bronchoscopy is generally the procedure of choice for suspected asphyxiating foreign bodies located in the trachea or major bronchi. In patients with non-life-threatening FBA, flexible bronchoscopy is typically performed [15].

When large foreign bodies completely or almost completely obstruct major upper airways (glottis, supraglottis, trachea), it is critical to ensure the patient is oxygenated and the airway is secured [16]. Support measures may include bag-valve-mask ventilation and endotracheal intubation. If ventilation is unsuccessful, an emergent cricothyrotomy or tracheotomy may be required if the foreign body is suspected to be above the vocal cords. Once the airway is secured, immediate inspection of the oropharynx (glottis, supraglottis) is indicated, as one-third of FBA cases presenting as acute asphyxiation are located in the supraglottis. Retrieval of the foreign body with Magill forceps can be safely performed using direct laryngoscopy (glottis, supraglottis) or with smooth or alligator forceps during rigid or flexible bronchoscopy (large central foreign body in the trachea or major bronchus) [17].

The choice of procedure for foreign body removal depends on the type of presentation, characteristics of the inhaled foreign body, its location, the duration it has been in the airway (if known), and local expertise. Anti-inflammatories and antibiotics are not routinely administered to patients with suspected or documented FBA. Antibiotics are indicated only in cases of clinically, radiologically, or microbiologically documented respiratory tract infections. However, their use should not delay foreign body extraction, even if pneumonia or sepsis is suspected [2].

Special Patient Groups

In the pediatric age group, moderate or high suspicion of FBA is suggested by any of the following:

Witnessed FBA, regardless of symptoms.
History of choking, with any subsequent symptoms or suspicious characteristics on imaging.
A young child with suggestive symptoms without another explanation, especially if there are suspicious characteristics on imaging. Suspicious symptoms include cyanotic spells, dyspnea, stridor, sudden onset of cough or wheezing (often focal and monophonic), and/or unilaterally diminished breath sounds.

The tracheobronchial tree should be examined in all cases with moderate or high suspicion of FBA, using rigid bronchoscopy (or, in some cases, computed tomography [CT]). On occasion, the adjunctive use of a flexible bronchoscope may be helpful. Normal chest radiographs are not sufficient to rule out FBA [19], primarily because most foreign bodies are radiolucent. Morbidity and mortality may increase if bronchoscopic evaluation is delayed.

When To Admit This Patient

Most patients improve clinically following FBA removal. Those with imaging abnormalities should undergo follow-up imaging six weeks to three months after extraction to confirm resolution. Patients presenting with a delayed presentation and belonging to high-risk groups should be admitted for management of complications and FBA retrieval and removal.

Revisiting Your Patients

The elderly patient, given his history of a recent stroke and being in a rehabilitation center, is at risk of FBA. His presentation with chronic cough and fever raises suspicion of pneumonia; however, the emergency medicine clinician should maintain a broad differential diagnosis based on further history, including foul-smelling sputum and nursing staff observations of difficulty swallowing and previous admissions for pneumonia. Such delayed presentations of FBA can occur in this age group. The patient’s management began with initial stabilization using oxygen support, along with workup for infection. Imaging modalities started with a chest plain film, which showed right lower lobe opacities but no clear foreign body. With suspicion for FBA still high, a chest CT scan was performed and revealed evidence consistent with FBA. The patient was started on broad-spectrum antibiotics, and bronchoscopy was scheduled as the definitive management for FBA. Follow-up bronchoscopy identified distal fragments of nuts impacted in the right lower lobe bronchus.

In the pediatric patient, the presentation is more acute and requires securing the airway. After placing the patient on a non-rebreather mask with 15L of oxygen, his saturation improved to 100%. Given the history of playing with a wallet, suspicion of coin aspiration was considered. A chest radiograph with posteroanterior and lateral views was performed, showing a rounded radiopaque structure in the right main bronchus. Airway support and supplemental oxygen should be provided until bronchoscopy is performed and the coin is retrieved.

Authors

Elhaitham Ahmed

Zayed Military Hospital, AbuDhabi

Khalifa Alqaydi

Zayed Military Hospital, AbuDhabi

Listen to the chapter

References

Ruiz, F.E. (2022) Airway foreign bodies in children, UpToDate. Available at: https://www.uptodate.com/contents/airway-foreign-bodies-in-children?search=airway+foreign+bodies+in+children&source=search_result&selectedTitle=1~83&usage_type=default&display_rank=1 (Accessed: 08 May 2023).
Shepherd, W. (2023) Airway foreign bodies in adults, UpToDate. Available at: https://www.uptodate.com/contents/airway-foreign-bodies-in-adults?search=adult+forign+body+&source=search_result&selectedTitle=3~150&usage_type=default&display_rank=3 (Accessed: 08 May 2023).
Bajaj D, Sachdeva A, Deepak D. Foreign body aspiration. J Thorac Dis. 2021;13(8):5159-5175. doi:10.21037/jtd.2020.03.94
Dabu J, Lindner M, Azzam M, et al. A Case of Chronic Cough and Pneumonia Secondary to a Foreign Body. Case Rep Med. 2017;2017:3092623. doi:10.1155/2017/3092623
Mîndru DE, Păduraru G, Rusu CD, et al. Foreign Body Aspiration in Children-Retrospective Study and Management Novelties. Medicina (Kaunas). 2023;59(6):1113. Published 2023 Jun 9. doi:10.3390/medicina59061113
Goodloe JM, Soulek J. Foreign Bodies . In: Rosen’s Emergency Medicine Concepts and Clinical Practice. 10th ed. Elsevier; 2023:666-681.
Hazra TK, Ghosh AK, Roy P, Roy S, Sur S. An impacted meat bone in the larynx with an unusual presentation. Indian J Otolaryngol Head Neck Surg. 2005;57(2):145-146. doi:10.1007/BF02907672
Swanson KL, Edell ES. Tracheobronchial foreign bodies. Chest Surg Clin N Am. 2001;11(4):861-872.
Kazmerski T, Dedhia K, Maguire R, Aujla S. Chronic Esophageal Foreign Body Presenting as Wheezing and Cough in a Toddler. Pediatr Allergy Immunol Pulmonol. 2014;27(3):151-153. doi:10.1089/ped.2014.0370
White JJ, Cambron JD, Gottlieb M, Long B. Evaluation and Management of Airway Foreign Bodies in the Emergency Department Setting. J Emerg Med. 2023;64(2):145-155. doi:10.1016/j.jemermed.2022.12.008
António P, Raffaella C, Luigia R. Plain Film and MDCT Assessment of Neck Foreign Bodies. 2014;1007/978-88-470-5406-6_1.
Svedström E, Puhakka H, Kero P. How accurate is chest radiography in the diagnosis of tracheobronchial foreign bodies in children?. Pediatr Radiol. 1989;19(8):520-522. doi:10.1007/BF02389562
Turk D, Moslehi MA, Hosseinpour H. Role of Flexible Fiberoptic Bronchoscopy in the Diagnosis and Treatment of Pediatric Airway Foreign Bodies: A 5-Year Experience at a Tertiary Care Hospital in Iran. Tanaffos. 2022;21(3):354-361.
Pavitt MJ, Swanton LL, Hind M, et al. Choking on a foreign body: a physiological study of the effectiveness of abdominal thrust manoeuvres to increase thoracic pressure. Thorax. 2017;72(6):576-578. doi:10.1136/thoraxjnl-2016-209540
Bodart E, Gilbert A, Thimmesch M. Removal of an unusual bronchial foreign body: rigid or flexible bronchoscopy?. Acta Clin Belg. 2014;69(2):125-126. doi:10.1179/2295333714Y.0000000006
Davis RJ, Stewart CM. Complete Glottic Obstruction by an Unusual Foreign Body. Otolaryngol Head Neck Surg. 2019;160(5):935-936. doi:10.1177/0194599818824298
Singh GB, Aggarwal D, Mathur BD, Lahiri TK, Aggarwal MK, Jain RK. Role of magill forcep in retrieval of foreign body coin. Indian J Otolaryngol Head Neck Surg. 2009;61(1):36-38. doi:10.1007/s12070-009-0031-7
White Upper Airway Foreign Bodies: Emergency department presentation, Evaluation and Management. emDOCs.net – Emergency Medicine Education. April 12, 2021. Accessed May 9, 2023. http://www.emdocs.net/upper-airway-foreign-bodies-emergency-department-presentation-evaluation-and-management/.
Pinto A, Scaglione M, Pinto F, et al. Tracheobronchial aspiration of foreign bodies: current indications for emergency plain chest radiography. Radiol Med. 2006;111(4):497-506. doi:10.1007/s11547-006-0045-0

Reviewed and Edited By

Arif Alper Cevik, MD, FEMAT, FIFEM

Physiologically Difficult Airway – Metabolic Acidosis

November 25, 2020November 7, 2020 ~ Jule Santos, Brasil ~ Leave a comment

Case Presentation

A 32-year-old male with insulin-dependent diabetes mellitus came to your emergency department for shortness of breath. He was referred to the suspected COVID-19 area. His vitals were as follows: Blood pressure, 100/55 mmHg; pulse rate, 135 bpm; respiratory rate, 40/min; saturation on 10 liters of oxygen per minute, 91%; body temperature, 36.7 C. His finger-prick glucose was 350 mg/dl.

The patient reported that he had started to feel ill and had an episode of diarrhea 1 week ago. He developed a dry cough and fever in time. He started to feel shortness of breath for 2 days. He sought out the ER today because of the difficulty breathing and abdominal pain.

The patient seemed alert but mildly agitated. He was breathing effortfully and sweating excessively. On physical examination of the lungs, you noticed fine crackles on the right. Despite the patient reported abdominal pain, there were no signs of peritonitis on palpation.

An arterial blood gas analysis showed: pH 7.0, PCO2: 24, pO2: 56 HCO3: 8 Lactate: 3.

The point-of-care ultrasound of the lungs showed B lines and small foci of subpleural consolidations on the right.

At this point, what are your diagnostic hypotheses?

Two main diagnostic hypotheses here are:

Diabetic ketoacidosis (Hyperglycemia + metabolic acidosis)
SARS-CoV2 pneumonia

We avoid intubating patients with pure metabolic decompensation of DKA if possible, as they respond to hydration + insulin therapy + electrolyte replacement well and quickly.

But in this scenario, the patient is extremely sick and has complicating medical issues, such as an acute lung disease decompensating the diabetic condition, probably COVID19. Considering these extra issues may complicate the recovery time and increase the risk of respiratory failure, you decide to intubate the patient in addition to the treatment of DKA.

You order lab tests and cultures. You start hydration and empirical antibiotics while starting preoxygenation and preparing for intubation.

Will this be a Difficult Airway?

Evaluating the patient for the predictors of a difficult airway is a part of the preparation for intubation. Based on your evaluation, you should create an intubation plan.

This assessment is usually focused on anatomical changes that would make it difficult to manage the airway (visualization of the vocal cords, tube passage, ventilation, surgical airway), thereby placing the patient at risk.

“Does this patient have any changes that will hinder opening the mouth, mobilizing the cervical region, or cause any obstruction for laryngoscopy? Does this patient have any changes that hinder the use of Balloon-Valve-Mask properly, such as a large beard? What about the use of the supraglottic device? Does this patient have an anatomical alteration that would hinder emergency cricothyroidotomy or make it impossible, like a radiation scar? ”

So the anatomically difficult airway is when the patient is at risk if you are unable to intubate him due to anatomical problems.

The physiologically difficult airway, however, is when the patient has physiological changes that put him at risk of a bad outcome during or shortly after intubation. Despite intubation. Or because of intubation, because of its physiological changes due to positive pressure ventilation.

With the anatomically difficult airway the fear is that you won’t be able to intubate the patient and they might die.

With the physiologically difficult airway the fear is that you will be able to intubate the patient and they might die.
— AirwayMan (@JohnCSakles) September 19, 2018

These changes need to be identified early and must be mitigated. You need to recognize the risks and stabilize the patient before proceeding to intubation or be prepared to deal with the potential complications immediately if they happen.

5 main physiological changes need attention before intubation are: hypoxemia, hypotension, severe metabolic acidosis, right ventricular failure, severe bronchospasm.

Back to our patient: Does he have physiologically difficult airway predictors?

SI (Shock Index): 1.35 (Normal <0.8) – signs of shock
P / F: 93 (Normal> 300) – Severe hypoxemia
pH: 7.0: Severe metabolic acidosis – expected pCO2: 20 (not compensating)
qSOFA: 2 + Lactate: 3 (severity predictor)

Physiologically Difficult Airway

"Severely critical patients with severe physiological changes who are at increased risk for cardiopulmonary collapse during or immediately after intubation."

Sakles JC, Pacheco GS, Kovacs G, Mosier JM. The difficult airway refocused.

Severe Metabolic Acidosis

In this post, we will focus only on the compensation of the metabolic part, but do not forget that this is a patient who needs attention on oxygenation and hemodynamics as well. That is, this is intubation with very difficult predictions.

What happens during the rapid sequence of intubation in severe metabolic acidosis?

To perform the procedure, the patient needs to be in apnea. During an apnea, pulmonary ventilation is decreased and the CO2 is not “washed” from the airway. These generate an accumulation of CO2, an acid, decreasing blood pH. In a patient with normal or slightly altered pH, this can be very well-tolerated, but in a patient with a pH of 7.0, an abrupt drop in this value can be ominous.

We know that the respiratory system is one of the most important compensation mechanisms for metabolic acidosis and it starts its action in seconds, increasing the pH by 50 to 75% in 2 to 3 minutes, guaranteeing the organism time to recover. So, even seconds without your proper actions can be risky for critical patients.

In addition, it must be remembered that increased RF is the very defense for the compensation of metabolic acidosis, and most of the time the organism does this very well. So if after the intubation the NORMAL FR and NORMAL minute volume are placed in the mechanical ventilator parameters, again there is an increase in CO2 and a further decrease in pH.

And what’s wrong? After all, a little bit of acidosis even facilitates the release of oxygen in the tissues because it deflects the oxyhemoglobin curve to the right, right?

Severe metabolic acidosis (pH <7.1) can have serious deleterious effects:

Arterial vasodilation (worsening shock)
Decreased myocardial contractility
Risks of arrhythmias
Resistance to the action of DVAs
Cellular dysfunction

What to do?

Always the primary initial treatment is: treating the underlying cause! In patients with severe metabolic acidosis, it is best to avoid intubation! Especially in metabolic ketoacidosis, which as hydration and insulin intake improves, there is a progressive improvement in blood pH.

Sodium bicarbonate

The use of sodium bicarbonate to treat metabolic acidosis is controversial, especially in non-critical acidosis values (pH> 7.2). If you have acute renal failure associated, its use may be beneficial by postponing the need for renal replacement therapy (pH <7.2).

As for DKA, where sodium bicarbonate is used to the ketoacidosis formed by erratic metabolism due to the lack of insulin and no real deficiency is present, its use becomes limited to situations with pH <6.9.

The dose is empirical, and dilution requires a lot of attention (avoid performing HCO3 without diluting!)

NaHCO3 100mEq + AD 400ml

Run EV in 2h

If K <5.3: Associate KCl 10% 2amp

I would make this solution and leave it running while proceeding with the intubation preparations.

Attention: Remember, according to the formula below, that HCO3 is converted to CO2, and if done in excess, is associated with progressive improvement of the ketoacidosis and recovery of HCO3 from the buffering molecules. In a patient already with limited ventilation, its increase can cause deviation of the curve for the CO2 increase, which is also easily diffused to the cells and paradoxically decrease the intracellular pH, in addition to carrying K into the cell.

H + + HCO3 – = H2CO3 = CO2 + H2O

Mechanical ventilation

I think the most important part of the management of these patients is the respiratory part.

If you choose the Rapid Sequence Intubation: Prepare for the intubation to be performed as quickly as possible: Use your best material, choose the most experienced intubator, put the patient in ideal positioning, decide and apply medications skillfully, to ensure the shortest time possible apnea.

You will need personnel experienced in Mechanical Ventilation and you must remember to leave the ventilatory parameters adjusted to what the patient needs and not to what would be normal!

I found this practice very interesting: First, you calculate what the expected pCO2 should be for the patient, according to HCO3:

Winter’s Equation (Goal C02) = 1.5 X HCO3 + 8 (+/- 2)

And then, according to this table, you try to reach the VM Volume Minute value.

Goal CO2	Minute Ventilation
40 mmHg	6-8 L
30 mmHg	12-14 L
20 mmHg	18-20 L

These are just initial parameters. With each new blood gas analysis repeated in 30 minutes to an hour, you re-make fine adjustments using the formula below:

Minute volume = [PaCO2 x Minute volume (from VM)] / CO2 Desired

With the treatment of ketoacidosis, new parameters should be adjusted, hopefully for the better.

Another safer option for these patients would be to use the Awake Patient Intubation technique so that you would avoid the apnea period. However, Awake Patient Intubation Technique is contraindicated in suspected or confirmed COVID-19 cases due to the risk of contamination.

That’s it, folks, send your feedback, your experiences, and if you have other sources!

References

Sakles JC, Pacheco GS, Kovacs G, Mosier JM. The difficult airway refocused. Br J Anaesth. 2020;125(1):e18-e21. doi:10.1016/j.bja.2020.04.008
Mosier JM, Joshi R, Hypes C, Pacheco G, Valenzuela T, Sakles JC. The Physiologically Difficult Airway. West J Emerg Med. 2015;16(7):1109-1117. doi:10.5811/westjem.2015.8.27467
Irl B Hirsch, MDMichael Emmett, MD. Diabetic ketoacidosis and hyperosmolar hyperglycemic state in adults: Treatment. Post TW, ed. UpToDate. Waltham, MA: UpToDate Inc. https://www.uptodate.com (Accessed on July 15, 2020.)
Cabrera JL, Auerbach JS, Merelman AH, Levitan RM. The High-Risk Airway. Emerg Med Clin North Am. 2020;38(2):401-417. doi:10.1016/j.emc.2020.01.008
Guyton AC, HALL JE. Tratado de fisiologia medica. 13a ed. Rio de Janeiro(RJ): Elsevier, 2017. 1176 p.
Kraut JA, Madias NE. Metabolic acidosis: pathophysiology, diagnosis and management. Nat Rev Nephrol. 2010;6(5):274-285. doi:10.1038/nrneph.2010.33
Calvin A. Brown III, John C. Sakles, Nathan W. Mick. Manual de Walls para o Manejo da Via Aérea na Emergência. 5. ed. – Porto Alegre: Artmed, 2019.
Smith MJ, Hayward SA, Innes SM, Miller ASC. Point-of-care lung ultrasound in patients with COVID-19 – a narrative review [published online ahead of print, 2020 Apr 10]. Anaesthesia. 2020;10.1111/anae.15082. doi:10.1111/anae.15082

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3D Video Laryngoscopes

May 4, 2020June 12, 2020 ~ Ibrahim Sarbay, Turkey ~ Leave a comment

Laryngoscopy can be described as endoscopy of the larynx, which used to facilitate tracheal intubation during general anesthesia or cardiopulmonary resuscitation. For decades, direct laryngoscopy has been the standard technique for tracheal intubation. But today, there are two main types of laryngoscopy: direct and indirect. Indirect laryngoscopy means the provider visualizes the patient’s vocal cords without having a direct line of sight. Indirect Laryngoscopy includes video laryngoscopes, fiberoptic bronchoscopes, and optically-enhanced laryngoscopes. Video laryngoscopy introduced in recent years and it aims to overcome the limitations of direct laryngoscopy by using a camera attached to the laryngoscope. While it has clear advantages over direct laryngoscopy, video laryngoscopy still has a high cost of investment. It remains a rare commodity for Emergency Medicine clinics, especially in resource-limited settings.

While the COVID-19 pandemic was affecting the world, the people who were under the most significant risk were healthcare workers. We know that the risk of transmission of the disease is quite high, especially when performing high-risk medical procedures such as endotracheal intubation. It is a known fact that personal protective equipment such as masks or face shields are very important in protection. But it is even more important to stay physically away from the patient whenever possible. When intubating a patient, video laryngoscopy has a clear advantage in terms of eliminating the need to approach the patient’s head and trying to have a direct line of sight.

Video laryngoscopy devices are expensive. But, if you think about the essential components of it, you can easily realize that it doesn’t have to be this way. You need a blade, a camera system, a display, and a way to attach the blade and the camera system. While laryngoscopy blades are essential for Emergency clinics anyway, I can safely assume every Emergency clinic has them. A camera system and a display are also both fairly cheap and easy to obtain for most of the places on earth. Find those three and voila! You have a cheap video laryngoscope (In this post, I will not elaborate on the technique of combining a normal blade with a video camera).

For those who want to go to the next level, there are some ways of making your very own prettier video laryngoscopy devices. You just need a 3D printer, but luckily it is possible to find 3D printers in many cities these days.

So here we go.

Umay

The pandemic paved the way for innovation in many ways. Numerous doctors from all over the world rolled up their sleeves to develop new medical devices. Yasemin Özdamar, an Emergency Medicine specialist from Turkey, designed 3D-printable video laryngoscope blades named “Umay” (possibly an allusion to Orkhon inscriptions) in pediatric and adult forms based on normal laryngoscope blades.

The printing files of these blades can be downloaded for free in formats suitable for printing with PLA material, which is frequently used in 3D printers, and PA12, which is preferred for more professional printing. You can download the files here: Pediatric – Adult.

AirAngel

AirAngel is a not-for-profit tutorial center dedicated to making video laryngoscopes accessible in under-resourced nations. You can purchase the blade or video laryngoscopy devices from their website with a fairly low price of US$100-180. You can also get the file of the blade for free and 3D print it yourself. Its design is really similar to a D blade. You can head to AirAngel’s website and grab the printing file now.

Here is an example tutorial for AirAngel:

In our tests (in Turkey), the cost of printing one blade approximately 50 Turkish Liras (roughly equal to US$7 with today’s exchange rates). We also bought a “Borescope USB Camera” with a camera head outer diameter of 5.5mm from our local internet store for approximately US$13 (A similar product from Amazon). So, the cost was US$20 in total, which is cheaper than AirAngel’s offer, and a lot cheaper than a conventional video laryngoscope. We have attached the camera to the blade using special parts on them and connected the camera to a phone. And under a minute, a video laryngoscope was born.

Please note: The intended purpose of these designs is to be used as a training tool. They do not replace any medical-grade video laryngoscope systems. They are not in any way approved medical device designs, nor have they been reviewed by the FDA or any other organization. Be aware that many plastics vary in strength, heat resistance, and chemical resistance. The strength and durability of the blade will vary depending on what you print it with. Harmful and life-threatening complications may occur if pieces break in the airway.

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Some Hints About Airway!

July 17, 2019September 4, 2019 ~ AlHanouv AlQahtani, KSA ~ Leave a comment

Introduction

The airway is one of the most critical topics in the ER. Read everything about the airway; it is not a waste of time. Even if you have to spend one year just for airway, it is worth it. You will always be confident in dealing with whatever situation that might come to you. Although reading is essential, practicing and getting experience on airway issues is essential too. So, reading along with exposing many patients is a great combination to achieve good skills.

Build your own skills by reading then summarizing your own words. As long as it is correct and safe, the way accomplishing or securing the airway may not be important in many patients.

Here are some tips in airway management at the Emergency Department (ED)

I will mention some points that might help in the management of typical scenarios at the ED. They might look random, but trust me, it is the real deal.

Preparations

Attach the patient to monitor
Check the vitals,
Check saturation continuously,
Open IV lines (2x) and attach a bag of normal saline,
If the blood pressure is low use pressure cuff on the fluid’s bag,
If the patient maintains oxygenation don’t bag, just leave the mask on. Moreover, do not forget; bagging is not a safe procedure.
Your equipment’s; choose your tube size depending on the patient’s size, size of the laryngoscope
Make capnography ready
Call the respiratory therapist, if you don’t have one, you check the ventilation machine by yourself
Keep bougie on the side, and SUCTION! Doesn’t matter Yankuer or not anymore, as long as it takes away whatever is on your way. Don’t go too deep to avoid vomiting.
Raise the bed highest, keep the level of the patient up to your chest or even higher, the higher the better.
Have someone on your side in case you needed tracheal manipulation or pressure to facilitate the view.

Pay attention to hemodynamic parameters

Never intubate before knowing the blood pressure readings.
Never intubate with low blood pressure below 90 systolic.
Resuscitate then intubate.
Neutral hemodynamic resuscitation (some studies tried the use of paralytic agent alone, with local anesthetic on the glottis, the same idea as awake intubation, in case of hemodynamic instability to avoid the use of induction agents that might decrease hemodynamics). The risk of using multiple doses of an induction agent can cause hemodynamic instability.
However, if there is no contraindication, you can think of using ketamine to help boost the blood pressure.
Double the dose of your medication if the patient has low cardiac output. As with low cardiac output, the medication won’t reach fast; it might take longer than 4 min. There is no harm in increasing paralytic agents ONLY IF THE AIRWAY IS NOT DIFFICULT. Induction agents can be used as boluses also, but again be careful if the patient is unstable as it might worsen the condition.

Here is a great video summarizing hemodynamic issues in airway management

Intubation and beyond

Use direct laryngoscopy first, use the old school equipment to keep your skills fresh, but keep the video laryngoscope ready on the side. Some experts recommends using video laryngoscope blade for direct laryngoscope and if you need, just look to the screen.
Still failed multiple trials with the laryngoscope? Consider difficult airway. One of the recommendations is to “leave the tube in the esophagus and insert another tube; the other opening is definitely the trachea.” By the way, there are tools to understand the difficulty of the airway, so know and use it.

Rapid Sequence Intubation (RSI) and Delayed RSI: Delayed RSI used mainly in the ICU, and many authors hate this term. However, there is no harm if the patient is maintaining oxygenation, you can give a sedative and look before proceeding to RSI. Just don’t call this approach “RSI.”
Rocuronium or Succinylcholine; both will paralyze the patient; it is not about which one is better; it depends on the type of airway you are dealing with. If it is a difficult airway, you do not want to use rocuronium and end up bagging the patient for one hour. Using a short-acting agent is a smart move.
However, if it is easy, use it as it would help in paralyzing the patient for an hour, but doesn’t mean the patient is fine, do not forget analgesia/sedation!
The tube is in, yay! Good for you, but your work is not done yet. All of us been through the situation where we jump into the airway, insert the tube and leave. This is not a skill lab; it is a real patient. The patient is not moving does not mean he is fine, you paralyzed him but he can still feel. Insert the tube, attach capnography, bag, auscultate, make sure of the level of the tube’s depth, order x-ray STAT then start analgesia/sedation infusion! No matter how naive you are or had a blackout, use midazolam and fentanyl! However, please learn other options too, because different patients may require different agents.
Propofol infusion, the bright side of Propofol is its analgesic and sedative effect, although it has a high risk of causing hypotension.
The dilemma of which medication to use, as for induction or paralyzing. No one can tell you that one medication is better than the other. Read everything about each medication, understand it, then you make your own mixture.

As long as you keep reading, and updating your knowledge, with of course practice and exposure to different type of situations, you will always know how to deal with every situation.

Airway Tips by Manrique Umana

March 22, 2019September 4, 2019 ~ iEM Education Project Team ~ Leave a comment

Dr. Manrique Umana from Costa Rica presented a fantastic lecture during the 30th Emergency Medicine Conference of Mexican Society in Cancun/Mexico. Every emergency physician should know the airway tips he gave in the talk. Moreover, medical students and interns should also be aware of these clues. Therefore, we asked him to summarize his speech for iEM. You will find English and Spanish version of the summary on the below videos. Enjoy!