Medical School · Year 3 · Emergency Medicine · includes a quiz and discussion video

Seminar 01: Approach to the Undifferentiated Patient

Year 3: Emergency Medicine Clerkship

Learning Objectives

By the end of this seminar, students will be able to:

1. Apply systematic approaches to undifferentiated patients
2. Conduct rapid primary and secondary surveys
3. Identify immediately life-threatening conditions
4. Prioritize differential diagnoses based on acuity
5. Utilize appropriate diagnostic testing in emergencies
6. Recognize when to escalate care

Seminar Outline

I. Triage and Initial Assessment

Emergency department triage represents the critical first point of contact where clinical decisions determine the speed and intensity of care delivery. The Emergency Severity Index (ESI) provides a standardized five-level framework that balances patient acuity with anticipated resource utilization to optimize department flow and patient safety. Level 1 patients require immediate life-saving intervention for conditions such as cardiac arrest or respiratory failure, while Level 2 patients present with high-risk situations including chest pain concerning for acute coronary syndrome or stroke symptoms demanding emergent evaluation. Levels 3 through 5 represent progressively lower acuity presentations, distinguished primarily by the number of resources anticipated for workup and treatment rather than time to physician contact.

The first impression, often called the "across the room assessment" or clinical gestalt, synthesizes multiple visual and auditory cues within seconds of patient encounter. Experienced clinicians rapidly assess appearance, work of breathing, and circulatory status to determine whether a patient appears sick or not sick before any formal evaluation begins. This gestalt incorporates observations about skin color, diaphoresis, respiratory effort, positioning, and level of consciousness that guide the urgency of subsequent evaluation. While clinical gestalt can be powerfully accurate, it must be combined with systematic assessment rather than used as a sole decision-making tool.

Vital signs constitute objective physiologic data that anchor the clinical assessment and reveal patterns suggesting specific disease processes. Abnormal values including heart rate below 60 or above 100, systolic blood pressure below 90 or above 180/120, respiratory rate below 10 or above 22, oxygen saturation below 94 percent on room air, or temperature abnormalities outside the 36 to 38.3 degree Celsius range demand attention and explanation. The Glasgow Coma Scale provides standardized assessment of mental status, with scores below 15 warranting investigation into the cause of altered consciousness. Serial vital signs often prove more valuable than single measurements, as trends reveal clinical trajectory and response to intervention.

Chief complaint categorization organizes the initial diagnostic approach by grouping presentations into symptom clusters that share common differential diagnoses and workup strategies. Pain presentations encompassing chest, abdominal, and headache complaints each trigger specific algorithmic evaluations targeting the most dangerous underlying conditions. Dyspnea, altered mental status, trauma, and bleeding represent additional major categories that guide the clinician toward appropriate diagnostic pathways. The chief complaint provides the initial framework but should never limit consideration of diagnoses outside the expected category when the clinical picture suggests otherwise.

<image>Panel A: ESI triage levels depicted with representative patient presentations and resource allocation guidelines. Panel B: First impression assessment showing appearance, work of breathing, and circulation evaluation at a glance. Panel C: Vital sign parameters with normal ranges and thresholds requiring urgent attention displayed graphically. Panel D: Chief complaint categories with common dangerous diagnoses requiring consideration for each presentation type.</image>

II. Primary Survey (ABCDE)

Airway assessment and management constitutes the first priority in any critically ill or injured patient because hypoxia kills rapidly and airway compromise prevents all other therapeutic interventions from succeeding. The initial evaluation determines whether the airway is patent, at risk, or compromised by listening for stridor, gurgling, or silence and observing for signs of obstruction such as retractions or paradoxical breathing. Patients who speak in full sentences generally have patent airways, while those with decreased consciousness, facial trauma, or progressive stridor require immediate intervention ranging from simple positioning maneuvers to definitive airway placement. In trauma patients, cervical spine protection must accompany all airway interventions until injury can be excluded through clinical examination or imaging.

Breathing assessment evaluates both the adequacy of ventilation and oxygenation through observation, auscultation, and objective measurement. Respiratory rate, depth, effort, and symmetry provide immediate information about respiratory status, while pulse oximetry and capnography offer quantitative data about oxygen delivery and carbon dioxide elimination. Life-threatening respiratory emergencies including tension pneumothorax, massive hemothorax, open pneumothorax, and flail chest must be identified during primary survey because they require immediate intervention rather than waiting for diagnostic studies. The decision to provide supplemental oxygen, non-invasive ventilation, or proceed directly to intubation depends on the severity of respiratory compromise and the patient's trajectory.

Circulation assessment focuses on identifying shock states and controlling hemorrhage before cardiac output fails to maintain organ perfusion. Rapid evaluation includes pulse rate and quality, blood pressure, capillary refill, skin color and temperature, and mental status as an indicator of cerebral perfusion. External hemorrhage demands immediate direct pressure or tourniquet application, while internal bleeding may require emergent procedural intervention such as tube thoracostomy or emergency laparotomy. Establishing intravenous access with large-bore peripheral catheters and initiating volume resuscitation with crystalloid or blood products addresses hypovolemia while the source of bleeding is controlled.

Disability assessment evaluates neurological function through the Glasgow Coma Scale, pupillary examination, and gross motor function to identify intracranial pathology or metabolic derangement requiring urgent intervention. Point-of-care glucose measurement represents an essential component because hypoglycemia causes altered mental status that mimics numerous neurological emergencies yet responds immediately to simple treatment. Lateralizing neurological findings suggest focal intracranial pathology from stroke or mass lesion, while symmetric depression of consciousness points toward metabolic, toxic, or global hypoxic etiologies. Exposure and environmental control complete the primary survey by ensuring full examination capability while preventing hypothermia, which compromises coagulation and increases mortality in critically ill patients.

<image>Panel A: Airway assessment algorithm showing progression from basic maneuvers through definitive airway establishment with cervical spine precautions. Panel B: Breathing evaluation demonstrating inspection, auscultation, and immediate interventions for life-threatening thoracic emergencies. Panel C: Circulation assessment with shock recognition signs and hemorrhage control techniques including tourniquet placement. Panel D: Disability evaluation showing GCS scoring, pupillary assessment, and point-of-care glucose measurement in the primary survey sequence.</image>

III. Resuscitation Priorities

Immediate life-saving interventions must be initiated simultaneously with assessment rather than waiting for complete evaluation when critical conditions are identified. Airway compromise demands securing the airway through basic maneuvers, supraglottic devices, or endotracheal intubation depending on the clinical scenario and available resources. Respiratory failure requires supplemental oxygen, assisted ventilation with bag-valve-mask, or mechanical ventilation to maintain oxygenation above 90 percent saturation and prevent respiratory acidosis. Cardiovascular collapse mandates intravenous access, volume resuscitation, vasopressor initiation, and identification of reversible causes such as tension pneumothorax or cardiac tamponade that require specific procedural intervention.

Shock recognition and classification guides resuscitation strategy because different shock types require fundamentally different therapeutic approaches despite sharing hemodynamic instability as a common feature. Hypovolemic shock from hemorrhage or severe dehydration responds to volume replacement with crystalloid and blood products while identifying and controlling the source of loss. Cardiogenic shock from pump failure requires careful fluid management, inotropic support, and potentially mechanical circulatory assistance while addressing underlying cardiac pathology such as acute myocardial infarction. Obstructive shock from tension pneumothorax, cardiac tamponade, or massive pulmonary embolism demands immediate relief of the obstruction through needle decompression, pericardiocentesis, or thrombolysis respectively.

Resuscitation team dynamics optimize care delivery by assigning specific roles that allow parallel task completion during critical illness management. The team leader maintains situational awareness, directs care, and makes key decisions without becoming absorbed in procedural tasks that distract from oversight. Designated airway, procedure, medication, and documentation roles ensure that essential tasks occur simultaneously and efficiently while preventing critical omissions. Closed-loop communication, where orders are acknowledged and confirmed upon completion, reduces errors and ensures team members share accurate mental models of the clinical situation and therapeutic interventions underway.

Continuous reassessment after each intervention determines effectiveness and guides subsequent management decisions in the dynamic resuscitation environment. Response to fluid resuscitation, improvement in vital signs following medication administration, or resolution of respiratory distress after intervention indicates therapeutic success. Failure to improve or clinical deterioration triggers immediate repeat of the primary survey to identify missed diagnoses or new problems requiring intervention. Trending clinical parameters over time rather than relying on single measurements provides the most accurate assessment of resuscitation effectiveness and patient trajectory toward stabilization or continued deterioration.

<image>Panel A: Immediate intervention priorities hierarchy showing airway, breathing, and circulation interventions with specific actions for each. Panel B: Shock classification matrix displaying hypovolemic, cardiogenic, obstructive, and distributive shock with distinguishing features and initial treatments. Panel C: Resuscitation team role assignments illustrating team leader, airway, procedure, medication, and documentation positions with responsibilities. Panel D: Reassessment cycle diagram showing continuous evaluation after interventions with decision points for escalation or de-escalation of care.</image>

IV. Secondary Survey

History acquisition in the emergency setting employs structured mnemonics to ensure comprehensive information gathering while maintaining efficiency in time-critical situations. The SAMPLE mnemonic captures symptoms, allergies, medications, past medical history, last oral intake, and events leading to presentation, providing essential context for clinical decision-making. The OPQRST framework structures pain assessment through onset, provocation and palliation, quality, radiation, severity, and timing to characterize symptom patterns that distinguish between diagnostic possibilities. Obtaining history from multiple sources including emergency medical services, family members, and medical records often proves essential when patients cannot provide reliable information due to altered consciousness, cognitive impairment, or critical illness.

The head-to-toe physical examination systematically evaluates all body regions to identify injuries or pathology that may not be immediately apparent from the chief complaint alone. Examination proceeds from head including scalp lacerations, pupillary abnormalities, and hemotympanum through neck assessment of jugular venous distension, tracheal position, and cervical spine tenderness to thorough chest and cardiovascular examination. Abdominal examination evaluates for distension, tenderness, guarding, rigidity, and masses while pelvic examination assesses stability and tenderness in trauma patients. Extremity examination documents pulses, deformity, sensation, and motor function, while complete neurological examination identifies focal deficits requiring further investigation.

Focused assessment tailors the examination depth and breadth to the presenting complaint while maintaining vigilance for pathology outside the expected diagnostic category. Patients presenting with chest pain require detailed cardiovascular, pulmonary, and gastrointestinal examination to distinguish between cardiac ischemia, pulmonary embolism, pneumothorax, and esophageal pathology. Abdominal pain presentations demand attention to peritoneal signs, vascular examination for aneurysm, and consideration of thoracic and genitourinary sources of referred pain. The focused approach maximizes examination efficiency while the systematic framework prevents tunnel vision that causes diagnostic errors by prematurely narrowing consideration of alternative diagnoses.

Documentation of the emergency encounter serves medical, legal, and communication purposes by creating a permanent record of clinical findings, reasoning, and decision-making. Time stamps establishing arrival time, vital sign measurement, and intervention timing create the chronological framework essential for quality metrics and medical-legal documentation. Objective description of physical findings using specific anatomic terminology provides clear communication that persists across care transitions and time. Documentation of medical decision-making articulating the differential diagnosis considered, rationale for testing and treatment decisions, and disposition reasoning demonstrates appropriate clinical judgment and protects against retrospective criticism when outcomes are poor despite appropriate care.

<image>Panel A: SAMPLE and OPQRST history mnemonics displayed with specific questions and information targets for emergency evaluation. Panel B: Head-to-toe examination sequence illustrated with key findings to identify at each body region. Panel C: Focused assessment approach showing chief complaint-driven examination priorities with examples for chest and abdominal pain. Panel D: Documentation elements checklist highlighting time-sensitive entries, objective findings, and medical decision-making components.</image>

V. Diagnostic Testing

Point-of-care testing provides rapid diagnostic information that guides immediate treatment decisions in time-critical emergency conditions. Bedside glucose measurement identifies hypoglycemia within seconds, allowing immediate treatment of a reversible cause of altered mental status or seizure. Lactate measurement reflects tissue perfusion adequacy and serves as both diagnostic marker and prognostic indicator in sepsis and shock states. Venous or arterial blood gas analysis reveals acid-base status, ventilatory adequacy, and oxygenation when pulse oximetry proves unreliable or additional metabolic information is needed. Point-of-care troponin and pregnancy testing further expand the diagnostic capability available at the bedside without laboratory turnaround time delays.

Laboratory studies sent to the central laboratory provide comprehensive metabolic, hematologic, and coagulation data that complement point-of-care testing for complete patient evaluation. The complete blood count identifies anemia requiring transfusion, leukocytosis suggesting infection, or thrombocytopenia complicating bleeding disorders or indicating consumptive coagulopathy. Comprehensive metabolic panels reveal electrolyte abnormalities, renal function impairment, and hepatic dysfunction that influence differential diagnosis and treatment planning. Troponin measurement for suspected acute coronary syndrome, lipase for abdominal pain evaluation, coagulation studies for bleeding assessment, and urinalysis for infection screening represent additional commonly indicated studies selected based on clinical presentation.

Imaging modalities are selected based on the clinical question, diagnostic sensitivity and specificity for suspected pathology, radiation exposure considerations, and availability constraints. Chest and abdominal radiographs provide rapid screening for pneumothorax, pneumonia, bowel obstruction, and free air, though limited sensitivity for many conditions necessitates advanced imaging when clinical suspicion remains high despite negative plain films. Computed tomography offers superior diagnostic capability for trauma evaluation, stroke imaging, pulmonary embolism detection, and abdominal pathology characterization, though radiation exposure and contrast requirements demand appropriate patient selection. Ultrasound provides radiation-free imaging ideal for pregnancy evaluation, gallbladder assessment, deep venous thrombosis detection, and procedural guidance while increasingly serving as a bedside extension of physical examination.

The electrocardiogram represents an essential diagnostic test that must be obtained and interpreted within minutes for any patient presenting with chest pain, syncope, palpitations, or dyspnea. ST-segment elevation meeting criteria for STEMI demands immediate activation of the cardiac catheterization laboratory and initiation of antithrombotic therapy without waiting for troponin results. Arrhythmia identification guides specific antiarrhythmic therapy, cardioversion decisions, and pacemaker requirement assessment. ECG patterns suggesting pulmonary embolism, electrolyte abnormalities, or drug toxicity provide diagnostic clues that direct further evaluation. The practice of obtaining and personally interpreting the ECG within ten minutes of arrival for chest pain patients represents a fundamental emergency medicine quality standard.

<image>Panel A: Point-of-care testing array showing glucose, lactate, blood gas, troponin, and pregnancy testing devices with turnaround times. Panel B: Laboratory test panels organized by clinical indication with common abnormalities and their diagnostic implications. Panel C: Imaging modality selection algorithm based on clinical presentation with radiation and contrast considerations. Panel D: ECG interpretation priorities highlighting STEMI criteria, dangerous arrhythmias, and patterns suggesting specific pathology.</image>

VI. High-Risk Presentations

Chest pain evaluation demands immediate consideration of life-threatening diagnoses that present with overlapping symptom patterns yet require fundamentally different treatments. ST-elevation myocardial infarction requires reperfusion therapy within ninety minutes of hospital arrival, making rapid ECG acquisition and interpretation the highest priority for any patient with potential cardiac ischemia. Aortic dissection presents with tearing chest or back pain radiating between the scapulae, often with blood pressure differentials between extremities, and is worsened rather than helped by anticoagulation and thrombolysis appropriate for STEMI. Pulmonary embolism causes chest pain and dyspnea with hypoxia out of proportion to physical findings, requiring anticoagulation and potentially thrombolysis or embolectomy for massive PE with hemodynamic instability.

Shortness of breath presentations encompass cardiac, pulmonary, and systemic etiologies that require careful differentiation to guide appropriate therapy. Pulmonary embolism must be considered in any patient with unexplained dyspnea and hypoxia, particularly those with risk factors for venous thromboembolism including immobility, malignancy, or recent surgery. Tension pneumothorax presents with unilateral absent breath sounds, hypotension, and tracheal deviation, requiring immediate needle decompression followed by tube thoracostomy without waiting for radiographic confirmation. Acute decompensated heart failure manifests with orthopnea, jugular venous distension, and pulmonary edema requiring diuresis and afterload reduction, while asthma and COPD exacerbations respond to bronchodilators, corticosteroids, and potentially non-invasive ventilation.

Abdominal pain presentations include multiple surgical emergencies that cause catastrophic outcomes if diagnosis and intervention are delayed. Ruptured abdominal aortic aneurysm classically presents with the triad of hypotension, pulsatile abdominal mass, and abdominal or back pain, though all three findings are present in a minority of cases. Mesenteric ischemia produces pain out of proportion to physical examination findings, particularly in patients with atrial fibrillation or other embolic sources, and progresses rapidly to bowel infarction if not recognized and treated emergently. Ectopic pregnancy must be considered in any woman of childbearing age with abdominal pain, as rupture causes life-threatening hemorrhage that requires emergent surgical intervention and aggressive resuscitation.

Altered mental status requires systematic evaluation to distinguish between metabolic, infectious, toxic, vascular, and structural etiologies requiring different interventions. Metabolic causes including hypoglycemia, hyponatremia, hypercalcemia, uremia, and hepatic encephalopathy are identified through laboratory evaluation and often respond to specific treatments addressing the underlying abnormality. Infectious etiologies ranging from urinary tract infection in elderly patients to meningitis and encephalitis require appropriate antimicrobial therapy initiated empirically when clinical suspicion is high. Toxic ingestions and withdrawal states frequently cause altered consciousness, making toxicologic evaluation and specific antidote administration important diagnostic and therapeutic considerations. Stroke, intracranial hemorrhage, and mass lesions causing altered consciousness require emergent neuroimaging and neurosurgical or neurological intervention.

<image>Panel A: Chest pain diagnostic algorithm showing parallel consideration of STEMI, aortic dissection, pulmonary embolism, and tension pneumothorax with distinguishing features. Panel B: Dyspnea evaluation pathway differentiating cardiac, pulmonary, and systemic causes with key examination and testing findings. Panel C: Abdominal pain danger signs matrix identifying presentations requiring immediate surgical consultation and intervention. Panel D: Altered mental status differential organized by VITAMINS mnemonic (vascular, infectious, toxic, autoimmune, metabolic, iatrogenic, neoplastic, seizure) with evaluation approach.</image>

VII. Decision-Making

Clinical gestalt represents the integration of pattern recognition, experience, and intuition that allows experienced clinicians to rapidly identify sick patients and probable diagnoses. This cognitive process synthesizes visual appearance, vital sign patterns, and symptom clusters into diagnostic hypotheses faster than analytical reasoning alone could achieve. The "sick or not sick" determination often proves remarkably accurate when made by experienced clinicians within moments of patient encounter. However, gestalt is subject to cognitive biases and must be combined with systematic evaluation to avoid premature diagnostic closure and confirmation bias that lead to missed diagnoses.

Clinical decision rules provide validated algorithms that standardize evaluation for specific conditions by quantifying risk and guiding appropriate test utilization. The HEART score stratifies chest pain patients for risk of major adverse cardiac events, guiding decisions about observation admission, stress testing, or discharge with outpatient follow-up. Wells criteria for pulmonary embolism and deep venous thrombosis combined with D-dimer testing create algorithmic pathways that safely reduce unnecessary imaging while identifying patients requiring definitive evaluation. Ottawa ankle and knee rules decrease unnecessary radiography for extremity injuries by identifying patients with negligible fracture risk based on clinical examination findings.

Cognitive errors contribute substantially to diagnostic failure in emergency medicine, where time pressure and high patient volumes create conditions favoring heuristic rather than analytical thinking. Anchoring occurs when initial diagnostic impressions persist despite contradictory evidence, causing clinicians to force new information into existing frameworks rather than reconsidering the diagnosis. Premature closure happens when the diagnostic search stops after a plausible diagnosis is identified without considering alternatives or confirming the diagnosis. Availability bias leads to overweighting diagnoses recently encountered or particularly memorable, while confirmation bias causes selective attention to evidence supporting preferred diagnoses while discounting contradictory information.

Managing uncertainty represents a core emergency medicine skill because definitive diagnoses often cannot be established during the emergency department encounter despite comprehensive evaluation. The "worst-first" approach prioritizes exclusion of dangerous diagnoses before considering benign alternatives, accepting that some patients with benign conditions will receive extensive workups to avoid missing life-threatening pathology. Shared decision-making incorporates patient values and preferences into disposition decisions when medical evidence does not clearly mandate a single approach. Safety-netting through explicit return precautions, scheduled follow-up, and clear documentation of diagnostic uncertainty protects both patients and clinicians when patients are discharged with working rather than definitive diagnoses.

<image>Panel A: Clinical gestalt illustration showing rapid pattern recognition in sick versus not sick determination with contributing visual cues. Panel B: Clinical decision rules summary table showing HEART, Wells, Ottawa rules with application criteria and outcomes. Panel C: Cognitive bias examples in emergency medicine with specific scenarios demonstrating anchoring, premature closure, and confirmation bias. Panel D: Uncertainty management strategies including worst-first evaluation, shared decision-making, and safety-netting documentation approaches.</image>

VIII. Disposition

Admission criteria reflect the intersection of medical necessity, patient safety, and healthcare resource utilization that determines appropriate level of ongoing care. Hemodynamic instability, ongoing symptoms requiring parenteral therapy, need for continuous monitoring, or high probability of clinical deterioration mandate inpatient admission. Diagnostic uncertainty regarding potentially serious conditions, need for serial examinations, or pending test results that may change management support admission for continued evaluation. Social factors including inability to obtain medications, lack of reliable follow-up access, or unsafe home environment may necessitate admission even when medical criteria alone might support discharge.

Observation status provides an intermediate level of care for patients requiring additional evaluation or monitoring beyond what can be accomplished in the emergency department but unlikely to require prolonged hospitalization. Risk stratification protocols for chest pain, syncope, and transient ischemic attack represent common observation unit applications where serial testing and monitoring over 24 to 48 hours clarifies diagnosis and disposition. Response to treatment for conditions such as asthma exacerbation or atrial fibrillation with rapid ventricular response can be assessed in observation status before determining need for inpatient admission. Clear protocols with defined endpoints and time limits optimize observation unit utilization and prevent observation status from becoming de facto short-stay hospitalization.

Discharge planning begins at initial evaluation and encompasses diagnosis communication, treatment instructions, medication provision, follow-up arrangement, and safety-netting through return precautions. Clear explanation of the working diagnosis, acknowledging uncertainty when present, establishes appropriate patient expectations and provides context for understanding instructions and return precautions. Specific activity restrictions, medication instructions including duration and potential side effects, and dietary modifications must be communicated both verbally and in writing at appropriate literacy levels. Arranged follow-up appointments rather than vague instructions to see a physician improve compliance and reduce return visits while ensuring continuity of care for evolving conditions.

Return precautions constitute the safety net that catches patients whose conditions worsen after discharge or who develop new symptoms suggesting dangerous alternative diagnoses. Specific rather than generic instructions identify symptoms that should prompt immediate return, creating clear decision rules patients can follow without medical expertise. Time-based precautions establish expectations about improvement trajectory and trigger return evaluation when conditions fail to improve as expected. Written instructions reinforced by verbal explanation using teach-back methodology confirm patient understanding and provide reference for family members or caregivers who may identify concerning changes the patient themselves might miss.

<image>Panel A: Admission criteria framework organized by medical, monitoring, procedural, and social factors requiring inpatient management. Panel B: Observation unit utilization pathways showing common protocols for chest pain, syncope, and treatment response assessment. Panel C: Discharge planning checklist including diagnosis explanation, medication instructions, follow-up arrangements, and warning signs. Panel D: Return precaution examples with specific symptom descriptions and time-based expectations for common discharge diagnoses.</image>

IX. Special Populations

Elderly patients present unique challenges because physiologic changes of aging alter disease presentations, diminish reserve capacity, and increase vulnerability to complications. Classic symptom presentations are frequently absent, with elderly patients often presenting with non-specific complaints such as weakness, falls, or confusion rather than typical symptoms of myocardial infarction, infection, or surgical abdomen. Baseline functional status rather than age alone predicts outcomes and guides aggressive versus palliative treatment approaches. Polypharmacy creates drug interaction risks and potential for medication-related adverse events that may masquerade as new disease processes. The threshold for admission should be lower in elderly patients given their limited physiologic reserve and vulnerability to rapid deterioration.

Pediatric patients require age-specific approaches to vital sign interpretation, history acquisition, physical examination, and procedural techniques. Normal vital signs vary dramatically with age, such that heart rate and respiratory rate values representing tachycardia in adults may be normal in infants, while hypotension represents a late and ominous finding in children who maintain blood pressure through vasoconstriction until decompensation. History depends heavily on caregiver report, though parental concern about child not acting right or being different from normal deserves serious consideration as parents know their children's baselines better than any clinician. Weight-based medication dosing, appropriately sized equipment, and modified procedural techniques accommodate the anatomic and physiologic differences between children and adults.

Immunocompromised patients including those with HIV, solid organ or stem cell transplantation, active malignancy, chronic corticosteroid use, or primary immunodeficiency require modified approaches to infection evaluation and treatment. Typical inflammatory responses may be blunted or absent, with failure to mount fever or leukocytosis despite serious infection. Opportunistic organisms not considered in immunocompetent hosts must enter the differential diagnosis, expanding empiric antimicrobial coverage and diagnostic testing. The threshold for admission, imaging, and empiric treatment should be lower given increased morbidity and mortality from infections that might be managed conservatively in immunocompetent patients.

Pregnant patients present the unique challenge of caring for two patients simultaneously while navigating altered physiology and medication safety constraints. Physiologic changes of pregnancy including increased heart rate, decreased blood pressure, expanded blood volume, and elevated white blood cell count alter interpretation of vital signs and laboratory values. Fetal concerns including radiation exposure, medication teratogenicity, and hemodynamic effects of maternal positioning require obstetric consultation and modified imaging and treatment approaches. Pregnancy-specific emergencies including ectopic pregnancy, preeclampsia, and obstetric hemorrhage must be considered in any pregnant patient presenting with abdominal pain, headache, or vaginal bleeding.

<image>Panel A: Geriatric emergency considerations showing atypical presentations, polypharmacy risks, and lower admission thresholds for elderly patients. Panel B: Pediatric vital sign reference ranges by age with normal values and thresholds indicating concern. Panel C: Immunocompromised patient evaluation approach with expanded differential diagnosis and modified treatment thresholds. Panel D: Pregnancy-specific considerations including physiologic changes, medication safety, and common pregnancy emergencies requiring recognition.</image>

X. Handoff and Communication

Structured handoff communication using standardized formats reduces information loss during care transitions and improves patient safety across the care continuum. The I-PASS framework structures handoff communication around illness severity, patient summary, action list, situation awareness regarding pending issues and contingencies, and synthesis by the receiving provider confirming understanding. This standardized approach ensures consistent information transfer regardless of the specific individuals involved and prevents omission of critical information during high-volume or time-pressured transitions. Electronic handoff tools that prompt specific information entry can supplement verbal communication while creating documentation of information transferred.

Closed-loop communication during resuscitation and procedural care ensures accurate message transmission and task completion in high-stress, high-stakes environments. The sender delivers clear, directed instructions using names to identify specific team members responsible for each task. The receiver acknowledges the instruction by repeating it back, confirming understanding and acceptance of the assignment. The sender confirms correct understanding, and the receiver reports back upon task completion, closing the communication loop and ensuring all parties share accurate knowledge of completed interventions.

Consultant communication requires preparation, focused presentation, and clear articulation of the clinical question to optimize specialist input and expedite patient care. Reviewing available information including imaging and laboratory results before placing the consultation demonstrates respect for the consultant's time and enables more productive conversation. The clinical question should be specific rather than requesting general evaluation, identifying what decision or action depends on the consultant's input. Appropriate characterization of urgency prevents both unnecessary delays in truly emergent situations and inappropriate escalation of routine consultations that generates friction between services.

Patient communication in the emergency department occurs under time pressure and emotional distress that impair information retention and comprehension. Plain language avoiding medical jargon improves understanding across patient education levels and reduces dangerous misunderstandings about diagnoses, treatments, and follow-up instructions. Teach-back methodology confirms comprehension by asking patients to explain in their own words what they understand about their condition and instructions. Empathic communication acknowledging patient concerns, providing honest time estimates about waits and results, and offering updates during prolonged evaluations improves patient satisfaction and trust even when medical outcomes cannot be immediately optimized.

<image>Panel A: I-PASS handoff framework diagram showing illness severity, patient summary, action list, situation awareness, and synthesis elements with example content. Panel B: Closed-loop communication sequence illustrating directed instruction, repeat-back acknowledgment, confirmation, and completion reporting. Panel C: Consultant communication structure with preparation elements, focused presentation components, and specific question formulation. Panel D: Patient communication strategies showing plain language translation, teach-back methodology, and empathic communication techniques.</image>

Summary

• ESI triage system uses five levels balancing acuity and resource utilization, with Levels 1-2 requiring immediate or emergent evaluation and Levels 3-5 distinguished by anticipated resource needs
• Primary survey follows ABCDE sequence: Airway with cervical spine protection, Breathing and ventilation, Circulation and hemorrhage control, Disability and neurological status, and Exposure with environmental control
• Shock classification into hypovolemic, cardiogenic, obstructive, and distributive types guides fundamentally different resuscitation approaches despite shared hemodynamic instability
• Secondary survey combines structured history using SAMPLE and OPQRST mnemonics with comprehensive head-to-toe physical examination
• High-risk chest pain diagnoses requiring immediate exclusion include STEMI, aortic dissection, pulmonary embolism, and tension pneumothorax
• Cognitive errors including anchoring, premature closure, and confirmation bias represent major sources of diagnostic failure in emergency medicine
• Clinical decision rules including HEART score, Wells criteria, and Ottawa rules standardize evaluation and optimize test utilization for specific conditions
• Disposition decisions integrate medical stability, diagnostic certainty, treatment requirements, follow-up capability, and social factors
• Special populations including elderly, pediatric, immunocompromised, and pregnant patients require modified evaluation approaches and lower intervention thresholds
• Structured handoff communication using I-PASS format with closed-loop confirmation reduces information loss during care transitions

Key Terms

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