You have a new patient!
A 56-year-old man presents to the Emergency Department with complaints of chest pain and dizziness that began an hour ago. Upon assessment by the triage nurse, his vital signs are as follows: his heart rate is 107 beats per minute, and his respiratory rate is 22 breaths per minute. His blood pressure is 96/70 mmHg, and his oxygen saturation is at 90% on room air. His temperature is 36.8°C.
You are the student on shift when this patient arrives, and immediately, your mind begins to jump across differential diagnoses for this patient. As you rush toward the patient’s room to join your senior, you prepare to list out all the potential causes of chest pain proudly. This must be a Myocardial Infarction, or maybe even an Aortic Dissection. Perhaps it is that rare Boerhaave syndrome you read about last night!
You finally catch up to the Emergency Physician, but before you can open your mouth to wax lyrical about esophageal ruptures, the Doctor states “Let’s begin by evaluating the ABCs.”
Initial Assessment
Emergency Medicine is one of the few specialties in medicine where patient evaluation begins in the same way for every patient, regardless of the probable diagnosis. Most clinicians are wired to jump straight to the ‘mystery-solving’ component of clinical presentation, with many undergraduate curriculums based around disease recognition. Emergency Medicine, however, places an emphasis on systematic assessment of the patient, starting with ‘The Primary Survey’.
The Primary Survey – ABCDE Approach
The Primary Survey aims to identify life-threatening conditions rapidly and systematically in critically ill patients, with appropriate stabilizing interventions performed when an abnormality is recognized. Besides streamlining the process in a high-stakes and often chaotic environment, the alphabetical order is designed first to address the most severe causes of mortality [1].
The Primary Survey aims to identify life-threatening conditions rapidly and systematically in critically ill patients, with appropriate stabilizing interventions performed when an abnormality is recognized. Besides streamlining the process in a high-stakes and often chaotic environment, the alphabetical order is designed first to address the most severe causes of mortality [1].
Airway
A patient’s airway connects air, and therefore oxygen, from outside the body to the lungs. Airway management is a term used to evaluate and optimize the passage of oxygen in the upper airway, which may be impaired when there is a blockage or narrowing of this pathway. The most common cause of upper airway obstruction is the tongue, which may ‘close’ the oropharynx posteriorly in patients who are comatose or in cardiopulmonary arrest, for example.
Assessment of the airway typically starts by evaluating any external features that may impact the passage of air through the naso- and oro-pharynx, such as facial or neck trauma, fractures, deformities, and any masses or swelling that may disrupt the airway tract. Allergies, especially anaphylaxis, and significant burns may cause edema of the laryngeal airway and produce obstruction. Excessive secretions may also congest the oropharynx and produce airway obstruction.
A patent or ‘normal’ airway allows a responsive patient to speak in full sentences without difficulty, implying a non-obstructed air passage down the oropharynx and through the vocal cords.
Clinical signs of obstruction may include stridor, gurgling, drooling, choking, gagging, or apnea. A physician may also identify an impending airway obstruction where loss of gag reflex, intractable vomiting, or worsening laryngeal edema may inevitably compromise the passage of air to the lungs and produce a failure to oxygenate or ventilate, prompting a decision to secure the tract through intubation.
Management
In the responsive patient, allow for the patient to be seated or lying in their most comfortable position as you assess the patency of the airway.
‘Opening’ the airway involves positioning the patient’s head in the ‘sniffing position’. In this position, a slight extension of the head with flexion of the neck, keeping the external auditory meatus in line with or above the sternal notch, is used to optimally align the pharyngeal and laryngeal airway segments, preventing obstruction posteriorly by the tongue (Figure 1). This is useful in patients who are unresponsive and cannot consciously protect their airway.
Two maneuvers are helpful in opening an unresponsive or sedated patient’s airway, optimizing air entry to the lungs:
1. Head tilt chin lift (Figure 2A) – Using fingertips under the chin, lift the mandible anteriorly while simultaneously tilting the head back using the other hand. Do not use this if cervical spine injury is suspected!
2. Jaw thrust (Figure 2B) – With thenar eminences of both hands anchored over both maxillary regions of the patient’s face, use your fingers at both angles of the mandible to lift it anteriorly. This maneuver is preferable in cases of suspected cervical spine injury as it does not cause hyperextension of the neck.
In unresponsive patients with excessive secretions, use of a rigid suction device can clear fluid and particulate matter such as vomitus.
Intubation may be performed if airway assessment deems it necessary to protect or secure the airway tract in a definitive way. If intubation is required, it should be performed as early as possible to prevent the evolution of a difficult airway, which would lower the chances of a successful intubation. It may also be useful to establish the risk of an inherently difficult airway using the L-E-M-O-N airway assessment method as below:
Look externally – facial trauma, large incisors and/or tongue, hairy beard, or moustache
Evaluate the 3-3-2 rule – where optimal distance between incisors on mouth opening should be 3 finger breadths. Similarly, 3 finger breadths (patient’s fingers) should span the distance from chin to hyoid bone, while the distance from hyoid to thyroid should measure 2 finger breadths.
Mallampati score – grades the view of an open mouth, with class 3 or more predicting a difficult intubation
Obesity/obstruction – Epiglottitis or a tonsillar abscess can inhibit easy passage of an endotracheal tube.
Neck mobility – if limited, positioning is difficult and causes suboptimal views during intubation.
Cervical spine immobilization
When the patient arrives in the Emergency Department (ED) following a significant physical trauma, such as head injury or motor vehicle collision, it is crucial to consider the integrity of the cervical spine. If injury is present in this region, further manipulation or movement of the neck may lead to spinal cord damage. Therefore, evaluation and management of airway for these patients should go hand in hand with cervical spine immobilization.
If no specialized equipment is available, or until one is prepared for use, attempts to limit neck movement can be done using manual in-line stabilization, where the provider’s forearms or hands may be positioned at the sides of the patient’s head to prevent indirect movements that could exacerbate underlying injury (see Figure 3).
Cervical spine immobilization is then performed using a rigid cervical collar. It may be augmented with head blocks on lateral sides to limit movement further as the patient is evaluated for injury (see Figure 4). The thoracolumbar region of the spine is immobilized using a spinal backboard, which keeps the patient in a supine position with minimal external force on the spine. Frequently utilized in Emergency Medical Services (EMS) during extrication and transport, all efforts should be made to transition the patient off the spinal board in the ED as it is quite uncomfortable, with prolonged use associated with pressure ulcers and pain.
Breathing
The lungs perform the vital function of delivering oxygen from the airway to the alveoli through ventilation. Perfusion at the alveoli allows for gas exchange; therefore, effective ventilation and perfusion both play a key role in the availability and utilization of oxygen by the human body. Evaluation of the Breathing component assesses factors that would indicate a compromise in ventilation.
The chest inspection should look for respiratory rate, use of accessory muscles, position of trachea (midline versus deviated), symmetry of chest rise, and/or any visible trauma to the thorax. Auscultation evaluates breath sounds for any bilateral inequal air entry or presence of crackles, crepitus, or wheeze. Percussion, though sometimes useful, is often difficult to perform adequately in a resuscitation environment.
Let’s compare the findings in normal lungs, pleural effusion, and pneumothorax based on chest rise, trachea position, percussion, and auscultation.
Normal Lungs: Chest rise is symmetrical with the trachea in the midline position. Percussion reveals a resonant sound. Auscultation presents vesicular breath sounds peripherally and bronchovesicular sounds over the sternum, with no added sounds.
Pleural Effusion: Chest rise remains symmetrical, and the trachea is midline. Percussion is dull over the area of effusion, and auscultation shows decreased breath sounds in the region of the effusion.
Pneumothorax: Chest rise is unequal, and the trachea may be deviated in cases of tension pneumothorax. Percussion reveals a hyper-resonant sound in the area of the pneumothorax, and auscultation shows decreased breath sounds over the pneumothorax region.
Measuring oxygen saturation using pulse oximetry (spO2) provides a percentage of oxygen in circulating blood, with normal levels typically at 95% or above. However, in patients with chronic lung disease, baseline oxygen saturation levels may decrease and can be as low as 88% in many cases. For patients experiencing shortness of breath and showing signs of hypoxia, pulse oximetry readings below 94% suggest that supplemental oxygen may be necessary. This can be administered through various oxygen delivery systems, as outlined in Figure 5 and described below.
General concepts—We typically breathe in room air, which contains 21% oxygen. Each Liter per minute of supplemental oxygen provides an additional 4% inspired oxygen (FiO2) to the patient.
Nasal cannula – Administered through patient nostrils, can provide a maximum flow rate of 4-6 Liters per minute of oxygen, which equals roughly 37 – 45% FiO2
Simple face mask – Applied over the patient’s nose and mouth, can provide a maximum flow rate of 6-10 Liters per minute of oxygen, which equals roughly 40 – 60% FiO2
Venturi mask – Typically used in COPD, where over-oxygenation is avoided. Different colors deliver various flow rates to limit oxygen delivery to the required amount only; Blue (2-4L/min, FiO224%), White (4-6L/min, FiO2 28%), Yellow (8-10L/min, FiO235%), Red (10-12 L/min, FiO2 40%), Green (12-15 L/min, FiO260%)
Non-rebreather mask – Utilizes an attached bag with a reservoir of oxygenated air along with one-way valves on the mask to prevent rebreathing of expired air, optimizing oxygenation. It can provide a maximum flow rate of 15 Liters per minute of oxygen, which equals roughly 85 – 90% FiO2.
Non-invasive ventilation (CPAP/BiPAP) is a tight-fitting mask device that uses high positive pressure to keep the airway open and enhance oxygenation. It is particularly useful in conditions such as COPD exacerbation, acute pulmonary edema/heart failure, and sleep apnea.
Bag-valve mask device: A self–inflating bag attached to a reservoir delivers maximal, high-flow 100% oxygen. This method of manual ventilation is used in rescue breathing and oxygen delivery in nonresponsive or cardiopulmonary arrest patients.
Circulation
The circulation component of the Primary Survey evaluates the adequacy of perfusion by the cardiovascular system. The patient’s general appearance is assessed for signs of pallor, mottling, diaphoresis, or cyanosis, which indicate inadequate or deteriorating perfusion status. Pulses are checked centrally (e.g. carotid pulse, especially if patient with impaired breathing) and peripherally (e.g. radial) alongside hemodynamic assessment, including blood pressure and heart rate checks. Information from this segment also provides valuable insight into potential signs of shock. Extremities are palpated in order to determine any delays in capillary refill time (more than 2 seconds signifies inadequate perfusion, e.g. hypovolemia), peripheral edema in lower extremities (signs of heart failure), and skin temperature (cool or warm to touch).
In cases of trauma, systematic evaluation of circulation also seeks to ascertain areas of potential blood loss or collection, with interventions for any long-bone deformities and/or bleeding from open wounds performed as they are discovered.
Intravenous (IV) line insertion is also performed as part of the management of circulation, as any required fluid or blood products can then be administered through a large-bore IV line (16 gauge or higher). If IV insertion is difficult on multiple attempts, when volume resuscitation is urgently required, Intraosseous (IO) access should be sought to prevent delay in any needed treatment. Insertion of a peripheral venous line often occurs concomitant to blood extraction for any urgent laboratory investigations and/or point-of-care testing. Some common examples of tests performed on critically ill patients include venous blood gas, complete blood count, type and crossmatch, troponin, urea, electrolytes, and creatinine.
Finally, circulation assessment requires an evaluation of cardiac rhythm. Basic auscultation may reveal the rate and regularity of rhythm along with murmurs. However, a critically ill patient will also benefit from the immediate attachment of cardiac pads to the bare chest and connection to a cardiac monitoring device, which provides the physician with the patient’s current cardiac rhythm.
A normal sinus rhythm (Figure 6) consists of a P wave (atrial depolarization), followed by a QRS wave (ventricular depolarization – normally less than 120 ms), with a subsequent T wave (ventricular repolarization). P-R intervals typically have a duration of 120 – 200 ms. A regular rhythm, with a consistent P wave preceding QRS complexes, with a normal heart rate (between 60 – 100 beats per minute (bpm)) is required to consider a rhythm to be normal sinus on the cardiac monitor.
The American Heart Association’s (AHA) Advanced Cardiac Life Support (ACLS) course and guidelines outline a series of internationally recognized cardiac rhythms and their general management when encountered [2]. Some of the most important rhythms, along with the AHA bradycardia and tachycardia algorithms, are summarized below:
Several different conditions, including abnormal heart conduction, damage to the myocardium, metabolic disturbances, or hypoxia, can cause bradycardia. A lower heart rate can result in decreased perfusion to end-organs, such as the brain, with resultant signs and symptoms such as dizziness, confusion, shortness of breath or chest pains. Management (Figure 7.2) aims to treat the underlying cause and increase the heart rate (atropine, dopamine/epinephrine and/or cardiac pacing) if needed to restore the heart’s ability to perfuse organs adequately.
Tachycardia (Figure 8.1) is a heart rate of more than 100 bpm that may present as several types of waveforms on the cardiac monitor. Supraventricular tachycardia (SVT) originates in the upper chambers of the heart. The rapid heart rate prevents adequate filling of the heart between contractions, causing signs and symptoms such as dizziness, palpitations, or chest pain.
Management (Figure 8.2) typically involves Valsalva maneuvers, medication (e.g. adenosine), and/or synchronized cardioversion as needed to revert the rhythm back to baseline.
SVT produces a narrow-complex tachycardia (QRS segments < 120 ms). In comparison, monomorphic Ventricular Tachycardia (Figure 8.3) originates in the lower chambers of the heart and produces a wide-complex (QRS segments > 120 ms) tachycardia on the cardiac monitor. Similarly, this rhythm may cause dizziness, shortness of breath, or chest pain and is managed with medication or synchronized cardioversion.
ACLS algorithms often divide patients based on “stable” and “unstable” categories. This grouping aims to ascertain which individuals have a pathology severe enough to impair cardiac output to the point of causing serious inadequacies in end-organ perfusion. This ‘instability’ is manifested by altered mental status, ischemic chest pain, drastically low hemodynamic parameters (e.g. systolic BP < 90 mmHg), signs of shock, and signs of acute decompensated heart failure.
Disability
This segment evaluates the level of consciousness and responsiveness of the patient. Level of consciousness may be assessed generally using the AVPU scale (below);
Alert: fully alert patient
Verbal: some form of verbal response is present, though not necessarily coherent.
Pain: response to painful stimulus
Unresponsive: no evidence of motor, verbal or eye-opening response to pain
or more explicitly, using the Glasgow Coma Scale (GCS)
| Choose the best response of patient |
|---|
| EYE OPENING |
| 4: Spontaneously |
| 3: To verbal command |
| 2: To pain |
| 1: No response |
| BEST VERBAL RESPONSE |
| 5: Oriented and converses |
| 4: Disoriented and converses |
| 3: Inappropriate words; cries |
| 2: Incomprehensible sounds |
| 1: No response |
| BEST MOTOR RESPONSE |
| 6: Obeys command |
| 5: Localizes pain |
| 4: Flexion withdrawal |
| 3: Flexion abnormal (decorticate) |
| 2: Extension (decerebrate) |
| 1: No response |
Exposure
Complete exposure of the patient may be necessary to completely evaluate for any external signs of infection, injury, and rash. This is especially useful in trauma, where log-rolling of the patient is included to ensure the back and spine are also included in a complete assessment for any traumatic injuries. As you expose the patient, obtain consent, be mindful of their dignity, and uncover each segment of the body sequentially, covering it back to prevent any hypothermia for the patient. A core temperature reading also completes vital sign measurements for the patient.
Practical implementation of the Primary Survey
The “cursory” primary survey
It may seem surprising to consider that virtually every patient who enters the Emergency Department, despite the severity of the illness, undergoes some form of a Primary Survey by the treating physician. However, the practicality of this becomes quite obvious when you consider a simple question frequently asked at the beginning of a patient encounter:
“How are you?”
An adequate response of “I am all right” or “Well, I have had this pain in my stomach…” seems fairly standard, but it addresses most of the components detailed in the previous section. A patient who can form words without difficulty or added sounds generally has an intact or patent Airway. Their ability to form words depends on air that has been sufficiently ventilated and moving through the vocal cords, hence the Breathing is adequate. An appropriate response to the question allows us to assume that Circulation adequately perfuses the brain to allow comprehension and formulation of new words oriented to the circumstances of the encounter, hence providing insight into Circulation and, to a degree, Disability.
Synchrony in the Emergency Department
Although systematic assessment during the Primary Survey is laid out in order, it is also important to note that an Emergency Department consists of teams of healthcare professionals who often have the personnel and resources to simultaneously perform tasks to efficiently address all components of the Primary assessment, without delay between segments.
In practice, an example of how synchrony works would involve a patient who, on initial, immediate assessment, is deemed to be in significant distress and/or critically ill. The patient is immediately moved into the ED to a resuscitation area, where team members expose the chest, attach cardiac pads to connect the patient to a cardiac monitor, obtain a fresh set of vital signs, including spO2monitoring, with IV cannula insertion, blood extraction for testing as needed. At the same time, a primary survey is conducted simultaneously by another physician who moves through Airway, Breathing, Circulation, Disability and Exposure. In more advanced systems, a member may be dedicated to each component of the Primary Survey.
Adjuncts
A number of resources are accessible to the Emergency Physician that may aid in diagnosing and investigating the critically ill patient. Utilizing these alongside the initial Primary Survey provides valuable, relevant information that can further guide clinical decision-making and diagnosis during evaluation.
- Electrocardiogram – A 12-lead electrocardiogram provides a complete picture of the heart’s electrical activity in various vectors and segments, allowing for a more accurate evaluation for rhythm disturbances, such as in acute myocardial infarction, hyperkalemia, bundle branch blocks, and torsade de pointes. This often ties into the Circulation assessment and allows for a more comprehensive look into the heart’s electrophysiology.
- Portable X-rays – Particularly in trauma, urgent chest and pelvic X-ray films can often be obtained without having to transfer the patient to Radiology, hence providing more information on suspected lung pathologies (e.g. pneumothorax, effusion/hemothorax) and pelvic abnormalities (e.g. fracture, displacement).
- Urinary/ gastric catheters – Urinary catheters are useful to evaluate fluid status and monitor output for the patient undergoing volume resuscitation. When relevant, gastric tube insertion can assist in gastrointestinal decompression, if needed, as well as minimize the risk of aspiration in certain patients.
- Point-of-Care Ultrasonography (PoCUS) – A rapidly evolving and increasingly prevalent modality in the ED is the ultrasound.[3] Various probes, at different frequencies, utilize ultrasound waves to provide the physician with real-time visualization of the body’s internal structures. These images are fast and often very reliable in determining major findings that can guide decision-making in critically ill patients (e.g. presence of post-traumatic intra-abdominal free fluid, pneumothorax, cardiac tamponade). Figure outlines some examples of information that can be extracted using PoCUS.
Reassessment
Each intervention performed in the Primary Survey should ideally be accompanied by a reassessment of vital signs and patient clinical status and a restarted Primary Survey beginning from Airway. Identifying any improvements, deteriorations, or non-responses that will be pivotal in guiding the initiation or discontinuation of further intervention as per the clinical case is crucial.
Focused History and Secondary Survey
If the patient is appropriately evaluated and stabilized following the Primary Survey, the treating physician may proceed with a focused history and secondary survey appropriate to the clinical circumstances. One example of a focused history incorporates the mnemonic SAMPLE to organize pertinent information as follows:
S – Signs/symptoms of presenting complaint
A – Allergies to any food or drugs
M – Medications (current, recent changes)
P – Pertinent past medical history
L – Last oral intake
E – Events leading to the illness or injury
A secondary survey in the Emergency Department is a more comprehensive physical examination performed systematically in a head-to-toe fashion to investigate any clinically relevant findings. In case of trauma, this also involves careful inspection for any missed injuries, deformities, or signs of underlying blood collection.
As the secondary survey is performed, relevant investigations and/or imaging may be ordered to augment the evaluation of the present clinical condition (e.g. Computerized Tomography (CT) of the brain after signs of basal skull fracture noted on inspection of the face and head). Information gathered from the survey and results of any ordered investigations, coupled with the clinical condition and/or response to therapy in the ED, if any, is used to determine patient disposition at the end of the ED encounter.
Revisiting Your Patient
You assist the Emergency Physician in performing a Primary Survey. The airway is patent, with the patient phonating in full sentences and breathing with mild tachypnea but no added sounds on auscultation. You initiate supplemental oxygen through a non-rebreather mask, with an increase in spO2 to 99%. You reassess and proceed through Airway, Breathing, and Circulation. As you discuss initiating IV fluids with your senior, the patient complains of worsening chest pain, palpitations, and dizziness.You attach the patient to the cardiac monitor and notice the rhythm below:
Cardiac pads have already been attached to the patient. Noting the presence of ischemic chest pain, you correctly identify the patient as having an unstable, narrow-complex tachycardia, most likely an SVT and prepare for synchronized cardioversion. Conscious sedation is conducted after explaining the procedure and obtaining consent from the patient. 50 joules of biphasic energy is then administered for synchronized electrical cardioversion. The rhythm changes on the monitor to the reading below:
You observe an organized rhythm but note that the patient is now unresponsive, with eyes closed and no palpable carotid pulse.
Basic Life Support
Cardiopulmonary arrest occurs when the heart suddenly stops functioning, resulting in lack of blood flow to vital organs in the body, such as the lungs and brain. Therefore, signs of arrest are manifested as a lack of breathing (apnea), lack of pulse and unresponsiveness. The most common cause of cardiac arrest is coronary artery disease.[4] Respiratory arrest refers to a cessation of lung activity, but with a present, palpable pulse and functioning heart.
The International Liaison Committee on Resuscitation (ILCOR) and the American Heart Association (AHA) are some of the key figures who have developed international guidelines on the recognition and management of cardiac arrest patients.[5] Basic Life Support (BLS) and Advanced Cardiac Life Support (ACLS) courses were established to optimize the workflow and, therefore, patient outcomes in Cardiopulmonary Resuscitation (CPR).
CPR forms the cornerstone of BLS to effectively maintain the victim’s circulatory and ventilatory function until circulation either spontaneously returns or is hopefully restored through intervention. The general concepts within BLS are outlined below:
1. A person who has a witnessed collapse, lack of response or who is suspected of being unresponsive due to cardiac arrest should be approached for further assessment and management. However, it is important for the rescuer to first determine whether the scene is safe around the patient before attempting any intervention. An example of this would be a victim drowned in water, who should be removed from the body of water onto a dry surface prior to attempting life-saving chest compressions or defibrillation.
2. Check for responsiveness. Firmly tapping both shoulders with the palms of your hands and a clear, verbal prompt, such as “Hey, are you okay?” should be incorporated to ensure that the victim is, indeed, unresponsive to an otherwise arousable stimulus.
3. You have determined that the patient is unresponsive. If you are alone, shout loudly and clearly for help and assistance. If no help is nearby, call Emergency Medical Services using your mobile phone.
4. Open the patient’s airway (tilt chin upward into sniffing position). Palpate the carotid pulse by placing two fingers (index and middle finger) just lateral to the trachea on the side closest to you while simultaneously observing the chest for any spontaneous chest rise (breathing). The pulse check should take a minimum of five (5) seconds but no more than 10 seconds to avoid delay in life-saving intervention.
5. When help is available, the chain of survival begins by activating the Emergency Response System. In addition to activating the Emergency Response, ask the person who has responded to your call for help getting an Automated External Defibrillator (AED) device. An example of instruction to a bystander (out of hospital) would be to ‘call an ambulance and get an AED!’. Inside a hospital, if another healthcare provider has come to aid, you may ask them to ‘activate the Emergency Response System/’Code Blue’ and get the crash cart/AED.’
6. Begin high-quality chest compressions. Hands are placed with fingers interlaced to exert pressure using the heel of one hand at the center of the chest, over the lower half of the breastbone (sternum), in line with the nipples (in men), with shoulders directly over your hands and arms straight at a perpendicular angle to the victim’s chest. High-quality chest compression is one of the few variables which have been evidenced to improve patient survival in cardiac arrest.
Keep the following features in mind to maintain high-quality chest compressions:
- More than 80% of the time in resuscitation or more should be spent on compressions (Chest compression fraction of > 80%)
- The frequency of compressions should follow a rate of 100–120 compressions per minute.
- Compression depth in adults is at least 2 inches. In infants and children, depth should be at least one-third of the anterior-posterior diameter of the chest.
- After each compression, the hands should be withdrawn to allow adequate chest recoil and fill the heart between compressions.
- Minimize interruptions in chest compression
- Avoid hyperventilation (see next point).
7. Compressions should follow the ratio 30:2, that is, 30 compressions followed by 2 rescue breaths delivered by a mouth barrier device (pocket mask) in the sniffing position or a Bag-valve mask (BVM) device if another rescuer is present to manage the airway in hospital. The BVM’s mask should be held with a tight seal using the E-C technique over the bridge of the nose and covering the mouth.
Breaths should be over 1 second, with enough air pushed in to observe a chest rise and no hyperventilation or excessive bagging of the BVM to avoid gastric insufflation. Two attempts at rescue breaths are performed, minimizing time to under 10 seconds and resuming chest compressions immediately after. If a definitive airway (e.g. endotracheal tube) is in place, resume compressions without pause at a rate of 100-120 compressions per minute while breaths are delivered once every 6 seconds.
8. Once an AED or cardiac monitor/defibrillator is available, place the pads on the victim’s bare chest (dry the skin if wet) in either an anterior-lateral or anterior-posterior position.When in doubt, follow the machine’s prompts and the instructions on the pads themselves to guide placement.
9. Follow the prompts on the AED. Stop compressions when the device analyzes rhythm and stay clear of the patient (not touching any part of the patient’s body). During an in-hospital resuscitation, as per ACLS workflow, stay clear, as the team leader should analyze the initial rhythm to ascertain the presence of a shockable or non-shockable rhythm. Either way, the device or team leader should prompt whether a shock is advised. Continue compressions as the device charges, but ensure that all rescuers are clear of the patient when the shock is delivered using the AED/defibrillator device.
A victim who is unresponsive but has a palpable pulse has respiratory arrest, which is managed using rescue breathing only. Breaths are delivered once every 6 seconds without chest compressions while transport to a higher level of care and/or management of any underlying cause for the condition is initiated.
Advanced Cardiac Life Support
The Advanced Cardiac Life Support algorithms were designed to deliver a higher level of resuscitative care where providers with increased training and improved resources are available. This type of augmented management is customary to the Emergency Department, where a Rapid Response Team or Code Blue team would respond when activated and initiate a more team-based approach to cardiopulmonary resuscitation.
Instead of an AED, in-hospital settings have a cardiac monitor/defibrillator, usually mounted atop a crash cart consisting of a CPR back-board (to support chest compressions by providing a firm surface to use under the patient’s chest), drawers with medication used during cardiac arrest, and various equipment for airway management and IV/IO access. Once brought to the bedside, the cardiac pads are similarly placed on the patient’s chest while BLS maneuvers (chest compressions and rescue breaths) continue. Once placed, however, compressions should be paused to assess the cardiac monitor’s cardiac rhythm. The type of rhythm should be identified as ‘shockable’ or ‘non-shockable’ (Figure 17s).
“Shockable” rhythms (pulseless Ventricular Tachycardia and Ventricular Fibrillation) are a product of aberrant electrical conduction of the heart. Rapid, early correction of this rhythm is the most important step in returning the body to its normal circulatory function. Early defibrillation is one of the few variables that has been evidenced to improve patient survival in cardiac arrest, the other notable one being high-quality chest compressions.[6]
Defibrillation involves using an asynchronous 200J of biphasic (360J if monophasic) energy, delivering an electric current through the cardiac pads attached to the patient’s chest to revert the heart to a rhythm that can sustain spontaneous circulation. Chest compressions should be ongoing while charging, but all persons should stay clear of the patient when shock is being delivered, and this is frequently verified with verbal feedback (‘Clear!’) before pressing the defibrillator button to deliver the shock. Immediately after the shock, chest compressions should resume to minimize interruptions between compressions.
Two minutes of chest compressions and rescue breaths make up each cycle of CPR, at the end of which a rhythm check should be performed for any changes and/or presence of pulse. Figure 18 outlines the ACLS algorithm used to manage shockable and non-shockable rhythms in cardiac arrest. Early shock in shockable rhythms is followed by a cycle of CPR, a second shock if still with a shockable rhythm, after which 1mg of IV epinephrine is given, with subsequent doses every 3 to 5 minutes. During the third cycle of CPR, after 3 shocks have been delivered for a persistent shockable rhythm, a bolus of IV Amiodarone 300mg is typically administered, with a dose of 150mg in a subsequent CPR cycle if still with a shockable rhythm.
“Non-shockable” rhythms (pulseless electrical activity (PEA) and asystole) are not typically a product of disorganized electrical activity in the heart. Instead, an underlying cause has resulted in cardiac arrest for these patients. While the majority of cardiac arrest is caused by coronary artery disease, the consideration of reversible causes by use of the H’s (hypovolemia, hypoxia, hyper-/hypokalemia, hydrogen ions (acidosis), and hypothermia) and T’s (thrombosis/embolism, toxins, tension pneumothorax, and cardiac tamponade) may help recognize and manage other possible etiologies in patients.
The management of non-shockable rhythms focuses on consistent, high-quality CPR, with regular pulse checks every 2 minutes, addressing reversible causes, and administering IV epinephrine 1mg every 3 to 5 minutes.
A palpable pulse with measurable blood pressure signals the Return of Spontaneous Circulation (ROSC).
Resuscitation Team Dynamics
The Emergency Department is equipped with the resources and personnel to provide care beyond basic life support. Resuscitation is optimized when multiple providers work together to effectively perform tasks toward management of the patient, thereby multiplying the chances of a successful outcome for the patient. A high-performance team typically consists of members allocated to the following roles and responsibilities:
- Airway – Opens and maintains the airway. Manages suctioning, oxygenation, and ventilation (Bag-valve mask) and assesses the need for a definitive airway if needed.
- Medication – Inserts and maintains IV/IO access. Manages medication administration and fluids.
- Monitor/defibrillator – Ensures attached cardiac pads and AED/cardiac monitor/defibrillator device are working appropriately to display the patient’s cardiac rhythm in clear view of the team leader. Administers shocks using the devices as needed. May alternate with the compressor every 5 cycles or 2 minutes to prevent compression fatigue
- Compressor – Performance of high-quality chest compressions as part of CPR for the cardiac arrest patient. Focuses on quality and consistency of compressions. You may switch to another standby compressor or monitor/defibrillator every 5 cycles or 2 minutes if compressions are affected by fatigue.
- Recorder – Documents the timing of medication, intervention (shocks, compression), and communicates these to the Team Leader, with prompts to enable timely dosing of frequent medication (e.g., ensuring epinephrine every 3 to 5 minutes is administered as per the verbalized order)
- Team leader – A defined leader who coordinates the team’s efforts and organizes them into roles and responsibilities that are clear, well-understood, and within their individual limitations. Provides explicit instructions and direction to the resuscitation effort, focused on patient care and optimized performance from all team members. Promotes understanding and motivates members, identifying any potential deficit or depreciation of quality during resuscitation and facilitating improvement in performance as needed.
All team members are encouraged to conduct themselves with mutual respect and practice closed-loop communication, where each message or order is received with verbal confirmation of understanding, then execution of the order, centralizing all information back to the team leader. Figure 19 provides an example of the possible placement of each member during resuscitation that may optimize their workflow through the resuscitation attempt. Ideally, the team leader remains at the foot of the bed, in clear view of all members, with involvement limited to coordination of the team’s efforts and minimal direct execution of tasks.
Post Arrest Care
If the patient is found to have Return of Spontaneous Circulation (ROSC), post-cardiac arrest care should be initiated to enhance the preservation of brain tissue and heart function. This involves a sequential assessment and optimization of Airway, Breathing, and Circulation in the initial stabilization phase. A definitive airway may be placed so ventilation is more appropriately controlled, with parameters set to optimize oxygen administered with ventilatory function. Figure 20 outlines the ACLS algorithm and parameters often used to help guide post-cardiac arrest care. Circulation incorporates fluids, vasopressors, and/or blood products to achieve an adequate systolic blood pressure above 90 mmHg, with Mean Arterial Pressure of at least 65 mmHg typically indicating perfusion within stable parameters.
It is imperative to obtain a 12-lead ECG early to ascertain the presence of an ST-elevation myocardial infarction (STEMI), which will require expedited transfer of the patient to a Cath Lab for definitive reperfusion therapy. The patient’s responsiveness should be reassessed, and the determination for additional investigation should be performed in conjunction with other critical care management as needed.
Of note, unresponsive patients may benefit from Targeted Temperature Management (TTM), which involves the maintenance of core body temperature at a target of 32 – 36 ℃ for 24 hours, or preferably normothermia at 36 °C to 37.5 °C with an emphasis on prevention of hyperthermia, in order to protect and optimize brain recovery post-arrest.[7]
Almost all cardiac arrest survivors will require a period of intensive care observation and management. If no immediate intervention is needed (e.g., reperfusion therapy), patients inside a hospital will need to be transitioned to an Intensive Care Unit (ICU) for further care.
What do you need to know?
- Emergency Medicine, especially in critical care, emphasizes a systematic approach to the unwell patient.
- The Primary Survey is designed to recognize and address life-threatening conditions effectively and timely.
- The Primary Survey components are Airway (& and C-spine in trauma), Breathing, Circulation, Disability, and Exposure.
- If an intervention is performed at any level of the survey, you must reassess the patient by commencing the Primary Survey again, starting with Airway.
- Reassess and review your patient for changes frequently.
- Many of the actions performed in the initial assessment of the critically ill patient may occur simultaneously when more team members are present in an Emergency Department. Do not let the chaos of the scene distract you from completing each step of the assessment.
- The AHA has well-established guidelines for assessing and managing patients through the Primary Survey. Use the algorithms and the patient’s status as ‘stable’ or ‘unstable’ to guide the management of recognized pathologies, especially in Circulation.
- The ED is home to a variety of adjuncts, including portable X-rays, ECG, and point-of-care ultrasound, which can provide the physician with rapid, readily accessible information to guide management.
- Remember the SAMPLE mnemonic for a focused history in the critically ill patient.
- An unresponsive patient should be immediately recognized, and Emergency Response Systems should be activated.
- Performance of Basic and Advanced cardiac life support focuses on preserving blood circulation transiently to maintain the perfusion of organs, such as the brain, until the cause of the condition is reversed or managed.
- The majority of cardiac arrest is caused due to coronary artery disease.
- The two most important predictors of patient survival in cardiac arrest are high-quality CPR and early defibrillation (for a shockable rhythm)
- An effective resuscitation in the ED often relies on the concerted efforts of multiple team members, led by a team leader who coordinates tasks in an organized, effective way to improve patient survival and outcomes.
Author
Mohammad Anzal Rehman
EM Residency Graduate from Zayed Military Hospital in Abu Dhabi, UAE. Founder/President of the Emirates Collaboration of Residents in Emergency Medicine (ECREM). Editor-in-Chief for the Emirates Society of Emergency Medicine (ESEM) Monthly Newsletter. I have a vested interest in sharing updated knowledge and developing teaching tools. As a healthcare professional, I continually strive to incorporate the newest clinical research into practice and am an active advocate for the use of Point of Care Ultrasonography (POCUS) in the ED.
Listen to the chapter
References
- Reynolds T. Basic Emergency Care: Approach to the Acutely Ill and Injured. World Health Organization; 2018.
- 2020 Advanced Cardiac Life Support (ACLS) Provider Manual. American Heart Association; 2021.
- Hashim A, Tahir MJ, Ullah I, Asghar MS, Siddiqi H, Yousaf Z. The utility of point of care ultrasonography (POCUS). Ann Med Surg (Lond). 2021;71:102982. Published 2021 Nov 2. doi:10.1016/j.amsu.2021.102982
- Cardiac Arrest Registry to Enhance Survival (CARES) 2022 Annual Report; 2022, https://mycares.net/
- Wyckoff MH, Singletary EM, Soar J, et al. 2021 International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations: Summary From the Basic Life Support; Advanced Life Support; Neonatal Life Support; Education, Implementation, and Teams; First Aid Task Forces; and the COVID-19 Working Group. Resuscitation. 2021;169:229-311. doi:10.1016/j.resuscitation.2021.10.040
- Soar J, Böttiger BW, Carli P, et al. European Resuscitation Council Guidelines 2021: Adult advanced life support [published correction appears in Resuscitation. 2021 Oct;167:105-106]. Resuscitation. 2021;161:115-151. doi:10.1016/j.resuscitation.2021.02.010
- Lüsebrink E, Binzenhöfer L, Kellnar A, et al. Targeted Temperature Management in Postresuscitation Care After Incorporating Results of the TTM2 Trial. J Am Heart Assoc. 2022;11(21):e026539. doi:10.1161/JAHA.122.026539
Acknowledgements
- Marina Margiotta – Illustrator
- Paddy Kilian – Emergency Physician – Mediclinic City Hospital, Dubai, Director of Academic Affairs – Mohammed Bin Rashid University Of Medicine and Health Sciences
- Rasha Buhumaid – Consultant Emergency Physician – Mediclinic Parkview Hospital, Dubai, Assistant Professor of Emergency Medicine – Mohammed Bin Rashid University Of Medicine and Health Sciences, President of the Emirates Society of Emergency Medicine (ESEM)
- Amog Prakash – Medical Student – Mohammed Bin Rashid University Of Medicine and Health Sciences
- Fatima Al Hammadi- Medical Student – Mohammed Bin Rashid University Of Medicine and Health Sciences
Reviewed 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.
