A 19-year-old woman stung by a bee develops generalised urticaria, stridor, and hypotension with a systolic BP of 70 mmHg. Central venous pressure is near zero and the extremities are warm with bounding pulses. The haemodynamic profile corresponds to which pattern?

• A Low systemic vascular resistance with high filling pressures and a low cardiac output
• B High systemic vascular resistance with low filling pressures and a low cardiac output
• C Low systemic vascular resistance with low filling pressures and a high cardiac output ✓
• D High systemic vascular resistance with high filling pressures and a preserved cardiac output

Explanation

Anaphylactic shock combines massive vasodilatation from mediator release with capillary leakage that drains the intravascular compartment. Systemic vascular resistance and filling pressures are low, while cardiac output remains high initially, giving warm, bounding pulses. Option B describes hypovolaemic shock with compensatory vasoconstriction. Option A resembles advanced septic shock with myocardial depression or obstructive patterns. High CVP with high SVR would fit cardiogenic or obstructive shock, not anaphylaxis.

Reference: Guyton and Hall Textbook of Medical Physiology, 14th ed.

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