Emergency Medicine: Structured Resuscitation and Time-Critical Reasoning
Emergency medicine questions reward a disciplined sequence: recognise the physiology that is about to kill the patient, intervene, then refine. Anchor your revision on the primary survey (airway with cervical spine protection, breathing, circulation, disability, exposure) and on the idea that each step is reassessed after every intervention rather than completed once. Know the reversible causes of cardiac arrest as the 4 Hs and 4 Ts, and be able to attach a clinical clue to each: hypoxia and hypovolaemia to a pre-arrest history, tension pneumothorax to unilateral absent breath sounds with hypotension, tamponade to distended neck veins with muffled heart sounds, toxins to the drug history. Understand shock as a failure of oxygen delivery, and classify it as hypovolaemic, distributive, cardiogenic or obstructive, because the first drug or fluid you choose follows from that classification.
Common traps include assuming a normal blood pressure excludes shock (compensated shock hides behind vasoconstriction and a narrow pulse pressure), and treating the monitor instead of the patient. Another trap is premature anchoring on a single diagnosis when the stem offers a distracting mechanism of injury.
Worked example
A young adult after a fall has a respiratory rate of 32, oxygen saturation of 91% on high-flow oxygen, absent breath sounds and hyper-resonance on the right, and a systolic pressure of 85 mmHg. The rule of thumb is: hypotension plus unilateral absent breath sounds equals tension pneumothorax until proven otherwise, and the treatment is immediate needle decompression before any imaging. Imaging is never the rate-limiting step in a decompensating patient.