Emergency medicine Study Guide

📖 Core Concepts Primary Survey (ABCDE) – Systematic, rapid assessment of Airway, Breathing, Circulation, Disability (neurologic status), Exposure (full body exam). Point‑of‑care ultrasound (POCUS) – FAST exam for intra‑abdominal free fluid, bedside cardiac view, procedural guidance. EMTALA – Federal law obligating every ED to provide a medical screening exam and stabilisation to any patient, regardless of ability to pay. Advanced Cardiac Life Support (ACLS) – Algorithmic approach to cardiac arrest, arrhythmias, and acute coronary syndromes. Rapid Sequence Intubation (RSI) – Quick airway control using induction agents + paralytics followed by endotracheal tube placement. Legal duty of care – Continuation of treatment until stabilised or properly transferred; premature termination = abandonment. 📌 Must Remember ABCDE order is never altered; each step must be completed before moving on. EMTALA penalties: up to $50,000 civil fine per violation; loss of Medicare provider status. Key labs: CBC, BMP, coagulation profile, cardiac troponins → essential for most acute presentations. ABG values: pH < 7.35 = acidosis, > 7.45 = alkalosis. PaCO₂ ↑ → respiratory acidosis; PaCO₂ ↓ → respiratory alkalosis. 12‑lead ECG findings: ST‑elevation → STEMI; new LBBB, Q waves, diffuse ST‑depression → ischemia. FAST positive = free fluid in peritoneal, pericardial, or pleural spaces → indicates trauma needing urgent intervention. 🔄 Key Processes Primary Survey (ABCDE) A: Secure airway; look for obstruction, apply jaw thrust, consider RSI. B: Assess breathing – look, listen, feel; give oxygen, consider needle decompression for tension pneumothorax. C: Evaluate circulation – check pulse, blood pressure, control external bleeding, start IV fluids/pressors. D: Determine disability – Glasgow Coma Scale, pupil size/reactivity. E: Expose patient, maintain normothermia, complete secondary exam. FAST exam Probe right upper quadrant → hepatorenal (Morison’s) pouch. Probe left upper quadrant → splenorenal recess. Subxiphoid view → pericardial space. Pelvic view → pouch of Douglas. RSI Workflow Pre‑oxygenate 3–5 min (100 % O₂). Prepare drugs (e.g., etomidate + succinylcholine). Apply cricoid pressure (Sellick maneuver). Rapidly induce, paralyze, then intubate. Confirm with end‑tidal CO₂ and bilateral breath sounds. ACLS Cardiac Arrest Algorithm Call for help, start CPR (30:2). Reshock if shockable rhythm (VF/VT). Epinephrine 1 mg IV/IO every 3‑5 min. Administer anti‑arrhythmics (e.g., amiodarone) as indicated. 🔍 Key Comparisons Airway → Endotracheal tube vs. Supraglottic airway ET tube: definitive airway, protects against aspiration, requires skill. Supraglottic: quicker, less skill‑dependent, used when intubation fails or as bridge. CT scan vs. Portable Chest X‑ray CT: high sensitivity for head injury, PE, abdominal trauma; higher radiation, need transport. Portable CXR: bedside, rapid for pneumothorax, pneumonia, cardiac silhouette; limited detail. EMTALA screening vs. Disposition Screening: any presenting complaint → medical history, physical, basic tests. Stabilisation: treat until safe to admit, transfer, or discharge; not a full work‑up. ⚠️ Common Misunderstandings “ABCD” can be skipped – The ABCDE sequence is mandatory; skipping any step risks missing life‑threatening problems. EMTALA allows “treat then discharge” without follow‑up – Discharge is only after adequate stabilisation and appropriate instructions; failure may be a violation. FAST negative = no injury – A negative FAST does not rule out retroperitoneal or spinal injuries; continue secondary survey. 🧠 Mental Models / Intuition “Airway‑Breathing‑Circulation” as a house – If the foundation (airway) is unstable, the whole structure collapses; always secure first. “Red flag vs. green flag” labs – Treat any red‑flag result (e.g., troponin rise, severe acidosis) as an immediate trigger for escalation. 🚩 Exceptions & Edge Cases Pregnant trauma patients – Modify exposure (shield abdomen) and consider left lateral tilt to improve uteroplacental flow. Patients with DNR orders – Must still perform the primary survey and provide stabilisation; respect documented wishes regarding resuscitation. Legal “refusal of treatment” – Competent adults may refuse even life‑saving care; document conversation, assess decision‑making capacity. 📍 When to Use Which Chest pain → 12‑lead ECG first, then cardiac biomarkers if ECG non‑diagnostic. Suspected intra‑abdominal bleed → FAST immediate; if positive, consider emergent CT if hemodynamically stable. Altered mental status → Obtain ABG early to rule out hypoxia/acidosis; order CT head if focal deficits or trauma. 👀 Patterns to Recognize ST‑segment elevation in contiguous leads → STEMI → activate cath lab. Tension pneumothorax signs – sudden unilateral absent breath sounds, tracheal deviation, hypotension → needle decompression. Triad of septic shock – hypotension, tachycardia, warm extremities → early broad‑spectrum antibiotics & fluid resuscitation. 🗂️ Exam Traps “EMTALA requires full work‑up” – The law mandates screening and stabilisation only, not exhaustive testing. “All patients need a CT” – CT is indicated for specific red‑flag findings; over‑use may be penalised for radiation exposure. “Supraglottic airway is always safer than intubation” – While faster, it does not protect against aspiration and is not a definitive airway in most critical cases. --- Keep this guide handy; review each bullet before the exam to reinforce the high‑yield facts and decision pathways that emergency physicians rely on daily.