Emergency and Critical Care Medicine
What this domain tests
This domain tests time-critical recognition and ordered action: airway, breathing, circulation, then focused history, with correct drug and dose selection. Questions frequently hinge on which action comes first or on a dose that must be exact.
Core rules
- Use a structured approach: catastrophic hemorrhage and airway first, then breathing, circulation, disability, exposure, followed by a secondary survey. Do not skip the secondary survey once stabilized.
- Anaphylaxis is a clinical diagnosis. Give intramuscular epinephrine 0.3 to 0.5 mg of the 1 mg/mL preparation into the anterolateral thigh, repeat every 5 to 15 minutes as needed, and give oxygen and fluids. Antihistamines and corticosteroids are adjuncts and never delay epinephrine.
- Cardiac arrest with shockable rhythm (ventricular fibrillation, pulseless ventricular tachycardia) receives immediate defibrillation and CPR; epinephrine 1 mg every 3 to 5 minutes and amiodarone after the third shock are standard additions.
- Sepsis: recognize organ dysfunction, draw cultures and lactate, and give broad-spectrum antibiotics within one hour for septic shock or high likelihood of sepsis, alongside fluid resuscitation.
- Acute ischemic stroke: intravenous thrombolysis is considered up to 4.5 hours from last known well after excluding hemorrhage; mechanical thrombectomy extends the window in selected large-vessel occlusion.
- ST-elevation myocardial infarction: reperfusion with primary percutaneous coronary intervention within 90 minutes of first medical contact where available.
- Tension pneumothorax is a clinical diagnosis treated immediately by needle decompression, then tube thoracostomy, without waiting for imaging.
Worked example
Ten minutes after an intravenous antibiotic, a patient develops urticaria, wheeze, and a blood pressure of 78/40. Reasoning: this is anaphylaxis with airway and circulatory involvement. Stop the infusion, call for help, give intramuscular epinephrine in the thigh immediately, position supine with legs elevated, give high-flow oxygen and a rapid crystalloid bolus, and prepare for a repeat dose and a difficult airway. Antihistamine is given later for skin symptoms; giving it first costs the patient the drug that actually reverses the reaction.
Traps that cost marks
- Delaying epinephrine while giving antihistamines.
- Giving the intramuscular dose intravenously in a non-arrest patient.
- Ordering imaging before decompressing a tension pneumothorax.
- Misattributing early shock or altered behavior to anxiety.
- Forgetting the secondary survey after the primary problem resolves.