ABCDE Archives

by Ibrahim Sarbay

Introduction

Emergency medicine differs significantly from other healthcare settings where patients are treated. Anyone can present to the Emergency Department (ED) at any time, on any day. Many patients may believe that the ED is capable of diagnosing and treating all their medical problems, as they are often unaware of the broader healthcare system’s structure and the specific purpose of EDs. Additionally, some patients may view the ED as a shortcut to quickly access medical care without the need for appointments. However, EDs worldwide are often overcrowded. As a result, Emergency Medicine (EM) physicians must evaluate patients as quickly as possible and proceed to the next patient waiting for care.

Furthermore, ED resources are limited. It is often not feasible to perform all the laboratory tests and imaging studies necessary for a definitive diagnosis within the ED setting.

Patients who present to the ED often believe they require urgent medical attention, and they are typically unfamiliar with the emergency physician treating them. This creates three critical challenges:

The patient is often anxious about their health condition and seeks quick, clear answers.
The physician must establish a relationship of trust with the patient in a very short time and under suboptimal conditions.
The physician may find it challenging to identify subtle changes in the patient’s condition at first glance, as they lack a baseline understanding of the patient’s “normal” appearance or state.

These challenges may initially seem daunting. However, as Dan Sandberg famously remarked, “Emergency Medicine is the most interesting 15 minutes of every other specialty.” Emergency physicians thrive on overcoming these obstacles by employing powerful and innovative approaches.

In this section, we will explore how Emergency Medicine specialists approach complex and undifferentiated patients in the ED, taking a journey through the thought processes and strategies of Emergency Medicine.

Triage

We mentioned above that EDs are unique. It is not possible to predict how many patients will present to the ED at any given time or how many resources will be required for their diagnosis and treatment. Triage is used both to evaluate the urgency of patients and to prioritize them accordingly, as well as to organize and evaluate EDs.

Patients admitted to the ED are first evaluated by a healthcare professional trained in triage, provided their clinical condition allows. The patient’s chief complaint and symptoms, vital signs, allergies, medications, past medical/surgical history, last food and drink, and a brief history of present illness are recorded. Afterward, the triage professional determines the patient’s triage level according to the triage system used in their ED.

There are various triage systems that are widely accepted worldwide. One of the most commonly used 5-level triage systems is the Emergency Severity Index (ESI) [1]. ESI classifies patients according to the severity of their complaints and the estimated number of resources needed, with level 1 being the most urgent and level 5 being the least urgent, as follows [2]:

ESI Level 1 (Immediate) – Patients with life-threatening conditions requiring immediate medical intervention.
ESI Level 2 (Emergent) – Patients with high-risk situations or severe distress, necessitating rapid attention.
ESI Level 3 (Urgent) – Patients with multiple or complex problems requiring multiple resources but able to tolerate a short wait.
ESI Level 4 (Semi-Urgent) – Patients with less complex issues, needing one resource and able to wait longer for care.
ESI Level 5 (Non-Urgent) – Patients with minor complaints, requiring minimal resources and able to wait without significant risk.

After the patient’s triage level is determined, he/she is directed to the appropriate area in the ED. The emergency physician begins the evaluation of the undifferentiated patient by reviewing the triage notes in the patient’s file.

For many patients, the triage notes provide sufficient information to formulate a probable diagnosis, enabling a focused examination without requiring a detailed clinical evaluation or further investigations. For example, if the triage notes indicate a patient is complaining of pain in their third finger after being hit by a ball while playing basketball, the physical examination can be focused on their hand.

However, patients presenting to the ED are often more complex, and the triage notes are frequently insufficient for making an immediate diagnosis. For these patients, a systematic approach is employed, starting with the Primary Survey, to identify the proper diagnosis and performing life saving actions.

Primary Survey

After quickly reviewing the triage notes, we proceed with the Primary Survey. In this stage, we aim to rapidly identify and address any life-threatening conditions using the ABCDE assessment. Each letter of ABCDE represents a distinct step of the evaluation: Airway, Breathing, Circulation, Disability, Exposure. At each step, we ensure there are no issues in the focused area of the patient. If any problems are identified, they must be managed before proceeding to the next step.

If the patient is conscious and alert, we may directly ask, “How are you?” If the patient’s eyes are closed or he/she appears unresponsive, we may touch his/her shoulder and ask, “Are you okay?” If the patient responds normally, it indicates that the airway is patent, breathing is adequate, and brain perfusion is sufficient. However, if the patient can only speak in short sentences, this may be a sign of respiratory distress. If the patient is completely unresponsive, this is a clear indication that he/she is in a critical condition.

Airway:

In the airway step, we aim to ensure that the patient’s airway is open and unobstructed. We check if the patient’s voice is clear and if breathing sounds are normal. We evaluate for signs of airway obstruction, such as facial trauma, swelling, hoarseness, or stridor. Conditions such as the presence of a foreign body in the mouth or excessive secretions may block the airway. In such cases, the patient may require aspiration of oral secretions.

If the patient’s airway is blocked by a foreign body, we encourage coughing. If he/she is unable to cough, we deliver back blows and perform abdominal thrusts (Heimlich Maneuver). If the patient becomes unresponsive, we proceed with cardiopulmonary resuscitation.

If there is a suspicion that the patency of the airway is at risk, we secure the airway with intubation or, if intubation is not possible, surgical airway techniques. If the patient’s oxygen saturation is low, we provide supplemental oxygen therapy.

For trauma patients, we assess for possible cervical spine injuries at this step and provide neck stabilization if necessary.

Breathing:

We evaluate whether the patient is breathing abnormally by checking the respiratory rate (12–20/min), observing chest wall movements, and performing chest percussion. We auscultate the lungs and monitor oxygen saturation levels (97–100%) using pulse oximetry.

A shift in the trachea’s position to one side at the suprasternal notch may indicate a mediastinal shift, which can occur with conditions like tension pneumothorax. If a tension pneumothorax is diagnosed, we perform decompression.

Chest expansion should be symmetrical; unequal expansion may occur with conditions such as pneumonia or thoracic trauma. Absent breath sounds may indicate airway obstruction, hyperinflation, pneumothorax, pleural effusion, or obesity. Additional respiratory sounds, such as wheezes, crackles, or stridor, may provide diagnostic clues [3].

Circulation:

We assess circulation by evaluating the patient’s pulse, blood pressure, and peripheral perfusion. If the patient has a radial pulse, it usually indicates that the blood pressure is within normal limits. If a radial pulse cannot be palpated, we check the carotid pulse.

Is the pulse irregular or weak? We palpate the pulse rate (60–100 bpm), assess skin color and sweating, auscultate the heart, and initiate cardiac monitoring. Capillary refill time, typically less than 2 seconds, can provide insight into peripheral perfusion, although external factors like cold environments or poor lighting may affect this assessment.

We also check for external bleeding, managing it with direct pressure and other necessary interventions. Low blood pressure combined with an increased pulse rate may indicate shock, requiring immediate fluid resuscitation via large-bore IV lines.

Disability:

We evaluate the patient’s neurological status by assessing level of consciousness, orientation, cooperation, facial symmetry, pupillary reflexes, and motor function.

The AVPU method is a quick tool for assessing consciousness:

A: Alert
V: Responds to verbal stimuli
P: Responds to pain stimuli
U: Unresponsive

Alternatively, the Glasgow Coma Scale (GCS) provides a more detailed neurological evaluation. Impaired consciousness is not always caused by neurological problems; conditions such as hypoglycemia, hypotension, hypercarbia, or carbon monoxide poisoning can also present with neurological symptoms. These can be excluded by evaluating pulse oximetry, finger-stick blood glucose, and arterial blood gas analysis.

Exposure:

We fully expose the patient to inspect the entire body for trauma, bleeding, rashes, needle marks, medication patches, or other abnormalities [4]. If the patient is a trauma victim, we ensure cervical spine immobilization during this step.

Completion of the Primary Survey:

Once the Primary Survey is completed, we address all identified life-threatening conditions. Patients deemed unstable by the emergency physician should always have vascular access, cardiac monitoring, and required blood tests performed. If necessary, oxygen therapy should be initiated. These interventions must be performed simultaneously, as time is critical in managing critically ill patients.

Differential Diagnosis

There may be thousands of diseases and clinical conditions that lead a patient to visit the ED. However, Emergency Medicine aims to distinguish potentially life-threatening conditions (life- or limb-threatening conditions) among these causes. We review vital signs, patient notes, and the results of the Primary Survey to formulate possible differential diagnoses.

Medical decision-making is a skill that can be developed over time through a combination of professional experience and accurate clinical information. Unfortunately, as humans, we are prone to cognitive biases [5]. However, understanding which cognitive biases exist and recognizing the most common mistakes in each clinical situation will undoubtedly enhance our success in clinical decision-making processes.

Secondary Survey

After treating our patient’s immediate life-threatening conditions and ensuring they are stable, the next step is the Secondary Survey. In this step, we take a focused history and perform a physical examination.

SAMPLE is an abbreviation commonly used in medical history-taking. By asking just six basic but very important questions, we can gain insight into the key aspects of the patient’s history: Symptoms, Allergies, Medications, Past Medical History, Last Oral Intake, and Events leading up to the illness or injury [6].

The SOCRATES acronym is a useful tool for further evaluating each of the patient’s current symptoms. Not every step may be suitable for every symptom; we focus on the steps that are appropriate for the symptom we aim to elaborate on. These steps are: the location of the complaint, its onset, character, radiation, associated symptoms, how it changes over time, exacerbating or relieving factors, and its severity. We ask the patient to rate the severity of the symptom (e.g., pain) on a scale of 1 to 10. This information is especially helpful for assessing changes in symptom severity following treatment (e.g., changes in the severity of pain).

The clinical condition of the patient also determines the extent of the physical examination we perform. For a patient presenting with a clear minor clinical diagnosis (e.g., foot sprain), an additional core physical examination may be sufficient. In contrast, for a critically ill patient (e.g., impaired consciousness), a comprehensive systematic physical examination is essential [7].

In the next step, we conclude by selecting diagnostic tests to support our differential diagnoses.

Clinical Decision Rules and Diagnostic Tests

At this stage of managing an undifferentiated patient, we should have a short list of probable diagnoses. Now is the time to reach the final diagnosis with the help of additional information. Focusing on the key points in signs & symptoms and physical examination, while differentiating each possible diagnosis, may help us achieve this goal.

Differential diagnoses for every major symptom are well-defined in the literature, and algorithms and clinical decision rules are widely available [8] (e.g., HEART Score or Ottawa C-spine Rules). Clinical Decision Rules are “evidence-based tools to assist the practitioner in decision-making for common complaints” [9]. While these rules are scientifically supported, they all have pearls and pitfalls. It is important to remember that they are not meant to replace critical thinking, and clinical decisions should not be made solely based on them.

There are many diagnostic tests that we can order in the ED. However, it is crucial to remember that we should never order a test simply because we can. When ordering a test, we must always consider its indications and (if any) contraindications, the way the test result will guide us, and its limitations. Therefore, a deep understanding of pre-test probabilities and test characteristics is essential for every clinician.

Decisions

The timeframe between the onset of symptoms in patients and their visits to the ED is not standardized. Sometimes, patients arrive at the ED within minutes (e.g., trauma). However, the patient may not show any signs of the disease at that exact moment, which may lead us to miss the real diagnosis. Therefore, it is vital to observe and re-evaluate patients multiple times over a period of time. This allows us to monitor the course of the illness, assess the effects of treatment, and ensure the accuracy of our initial diagnosis.

There are three possible decisions for an ED patient: hospital admission, transfer, or discharge. While each illness diagnosed in the ED has different admission and discharge statistics available in the literature, factors such as the capabilities of our facility, severity of the disease, comorbidities, and social support status influence the decision for each patient. As the sayings go: “Treat the patient, not just the disease” (Hominem non morbum cura) and “Treat the patient, not just the lab results.”

Sometimes, the need for admission will be clear to both you and the consultant. At other times, you may be certain that the patient requires admission, but the consultant may disagree. Similarly, some patients may accept your decision for admission, while others may not. In every scenario, it is essential to stay on the patient’s side and ensure that the chaotic moments in the ED or your own fatigue do not deprive the patient of the medical care he/she deserves.

To draw an analogy, consider construction sites: safety nets are installed to catch falling workers and reduce the likelihood of injury or mortality. If we think of the ED as a construction site, patients who are incorrectly discharged are akin to individuals falling from heights without a safety net. Telling patients, “You have no problems, you are just fine” without providing further guidance during discharge could result in missed opportunities for correction. Should the patient’s condition worsen, they might not return to a health facility, relying on the false assurance that they were told they had no issues.

This is why discharge recommendations are critically important—a concept known as “safety netting.” For example, let’s assume we are discharging a patient who presented with abdominal pain, and all investigation results are within normal limits. By explaining the red flags of abdominal pain and advising the patient to return to the ED immediately if symptoms worsen, we increase the likelihood that they will seek care again if needed, giving us a second chance. The difference between saying “You don’t have anything wrong” and “There are no signs of an emergency for now, but…” is as significant as the difference between installing a safety net at a construction site and not installing one.

Never say, “It won’t happen to me/my patient” out of false optimism. Remember, “Whatever can happen, will happen,” and as healthcare providers, we must always remain skeptical and prepared for any eventuality.

After all, a life is at stake.

Author

Ibrahim Sarbay

Ibrahim Sarbay is an Emergency Medicine Specialist living in İstanbul, Turkey. He graduated from KOU School of Medicine in 2011 and has a Master's Degree in Health Care Administration. He is particularly interested in managing Emergency Departments, working on decision support systems & diagnostic algorithms, and improving patient care in underrepresented patient groups. Writing online since 2002, Sarbay has published more than 1,000 posts mostly about science, life tips, self-improvement, and values. He co-founded Opereyşın, one of Turkey's most notable community blogs, in 2005. He was selected as a Top Writer of Medium Turkey in 2016. He won the Young Talents Award at TATKON 2019 Congress. His dissertation was one of the very first dissertations about COVID-19 published in Turkey. Currently, he writes for a favorite Turkish FOAMed blog, acilci.net, and iEM Education Project. He also shares his journey of learning through social media and likes researching, web programming, and making infographics.

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References

Kuriyama A, Urushidani S, Nakayama T. Five-level emergency triage systems: variation in assessment of validity. Emerg Med J. 2017;34(10):703-710. doi:10.1136/emermed-2016-206295.
Gilboy N, Tanabe P, Travers D, Rosenau A, Eitel D. Emergency Severity Index, Version 4: Implementation Handbook. Rockville, MD: Agency for Healthcare Research and Quality; 2005.
Sarkar M, Madabhavi I, Niranjan N, Dogra M. Auscultation of the respiratory system. Ann Thorac Med. 2015;10(3):158-168. doi:10.4103/1817-1737.160831.
Thim T, Krarup NH, Grove EL, Rohde CV, Løfgren B. Initial assessment and treatment with the Airway, Breathing, Circulation, Disability, Exposure (ABCDE) approach. Int J Gen Med. 2012;5:117-121. doi:10.2147/IJGM.S28478.
Morgenstern J. Decision Making in Emergency Medicine: We can’t escape bias. First10EM. March 7, 2022. doi:10.51684/FIRS.125798.
The Art of Questioning – Part 1. REAL First Aid. Accessed January 1, 2025. https://www.realfirstaid.co.uk/sample
Rodriguez RM, Phelps MA. An evaluation of the core physical exam in patients with minor peripheral chief complaints. Emerg Med J. 2007;24(12):820-822. doi:10.1136/emj.2007.050336.
Cowley LE, Farewell DM, Maguire S, Kemp AM. Methodological standards for the development and evaluation of clinical prediction rules: a review of the literature. Diagn Progn Res. 2019;3:16. doi:10.1186/s41512-019-0060-y.
Chamberlain S. Clinical Decision Rules. International Emergency Medicine Education Project. Accessed January 1, 2025. https://iem-student.org/clinical-decision-rules/

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.

Case

Jane Doe, 22-year-old female, was in a major car crash and is approaching the trauma bay via an ambulance. You are aware that the patient’s condition is critical, so you do a quick run-through in your head about the approach that you will have to care for them once they arrive to your emergency department. What should your approach to a trauma patient be?

The ABCDE of Trauma Care

The Airway, Breathing, Circulation, Disability, Exposure (ABCDE) approach is a clinically proven approach to any critically ill patient that needs emergent care and treatment. It has been proven to improve patient outcomes, optimize team performance and save time when patients are in life-threatening conditions [1]. This approach is applicable to all patients (both adults and children), regardless of their underlying condition. However, the ABCDE approach is not applicable to patients who are in cardiac arrest, in which case the cardiopulmonary resuscitation guidelines should be used [2].

With the ABCDE approach, initial assessment and treatment are performed simultaneously. Once the entire survey is completed, reassessment should be conducted until the patient is stable enough for the care team to be able to move on to the secondary survey and look for a definitive diagnosis.

A - Airway

First, the care team should assess if the patient’s airway is patent. If the patient responds to the team in a normal voice, then that is a good sign that the airway is intact. It is important to note that airway obstruction can be complete or partial, and can be caused by upper airway obstruction or reduced level of consciousness.

Signs of complete airway obstruction are lack of respiration despite great effort. Signs of partial airway obstruction include:
– Changes in the patient’s voice
– Snoring or gurgling
– Stridor (noisy breathing)
– Increased breathing effort

Assess the patient’s airway by looking for rocking chest wall motion and any signs of maxillofacial trauma or laryngeal injury. Perform the head-tilt and chin-lift maneuver to open the airway (note that caution should be conducted in patients with C-spine injury). If there is anything that is noticeably obstructing the airway, suction or remove it. If possible, remove foreign bodies that are causing airway obstruction. Provide high-flow oxygen to the critically ill patient and perform definitive airway if needed [1].

B – Breathing

Generally, airway and breathing are examined simultaneously. Determine if breathing is intact by assessing the respiratory rate, inspecting the chest wall movement for symmetry, depth, and respiratory pattern. Additionally, assess for tracheal deviation and use of respiratory muscles. Percuss the chest for dullness or resonance, auscultate for breath sounds and apply a pulse oximeter [1].

Injuries that impact breathing should be immediately recognized, and life-threatening injuries should be addressed and managed [3]. For example, tension pneumothorax must be promptly relieved by needle thoracocentesis, bronchospasms should be managed with inhalation and assisted ventilation should be considered if breathing continues to be insufficient [1].

C – Circulation

Conditions that threaten the patient’s circulation and can be fatal include shock, hypertensive crises, vascular emergencies such as aortic dissection and aortic aneurisms. These conditions should be immediately identified and managed [1].

Circulation can be assessed by looking at the general appearance of the patient, including signs of cyanosis, pallor, flushing and diaphoresis. Assess for any obvious signs of hemorrhage, blood loss and level of consciousness. Additionally, capillary refill time and pulse rate should be assessed. Auscultate the chest for heart sounds, and blood pressure measurement and electrocardiography should be performed as soon as possible [1].

Additionally, assess for signs of hypovolemia and shock. If these are identified, obtain an intravenous access and infuse saline to restore circulating volume [1]. If there are life-threatening conditions that are compromising the patient’s circulation, promptly identify and treat them as needed. For example, tension pneumothorax should be immediately treated with needle decompression and cardiac tamponade can be relived with pericardiocentesis.

D - Disability

The main disability in the primary survey to be assessed for is the brain. Abnormal neurological status can be caused by primary brain injury or systemic conditions that effect brain perfusion, such as shock, hypoxia, intoxication etc. Assess the level of consciousness by using the Glasgow Coma Scale [4], look for pupillary response and limb movement.

The best way to prevent injury to the brain is to maintain adequate airway, breathing and circulation. Glucose levels can be assessed at bedside for decreased level of consciousness due to low blood glucose levels, and corrected with oral or infused glucose [1].

E – Exposure

The exposure portion of the ABCDE approach involves assessment of the whole-body to avoid any signs of missing injuries. During this part of the management, undress the patient fully and examine the back for any signs of C-spine precautions. Additionally, check for clues for any signs of underlying conditions, such as:

Signs of trauma (i.e. burns, gunshot wounds, stab wounds)
Rashes
Causes of sepsis (i.e. infected wounds, gangrene)
Toxins and drugs (i.e. needle track marks, chemicals, patches)
Other wounds such as bite marks, insect bites, embedded ticks
Iatrogenic causes (i.e. catheters, tubes, implants, surgical sites and scars)

Concluding Remarks

The ABCDE approach to the critically ill patient is a strong and proven clinical tool for initial assessment and treatment of patients in medical emergencies. Widespread knowledge of this skill is critical for healthcare workers and any team providing emergent care to trauma patients.

*Note that this is a general approach to the trauma patient. Always consult your care team for adequate management of trauma patients and resort to reliable resources for more information on the ABCDE approach.

References and Further Reading

Thim, T., Krarup, N. H. V., Grove, E. L., Rohde, C. V., & Løfgren, B. (2012). Initial assessment and treatment with the Airway, Breathing, Circulation, Disability, Exposure (ABCDE) approach. International journal of general medicine, 5, 117.
Koster, R. W., Baubin, M. A., Bossaert, L. L., Caballero, A., Cassan, P., Castrén, M., … & Sandroni, C. (2010). European Resuscitation Council Guidelines for Resuscitation 2010 Section 2. Adult basic life support and use of automated external defibrillators. Resuscitation, 81(10), 1277-1292.
Subcommittee, A. T. L. S., & International ATLS Working Group. (2013). Advanced trauma life support (ATLS®): the ninth edition. The journal of trauma and acute care surgery, 74(5), 1363-1366.
Sternbach, G. L. (2000). The Glasgow coma scale. The Journal of emergency medicine, 19(1), 67-71.