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Citrate Toxicity Massive Transfusion — FRCA Final MCQ

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ModerateTrauma & Emergency AnaesthesiaCitrate Toxicity Massive TransfusionFRCA Final

A trauma patient receives 8 units of PRBC and develops tingling around the mouth, muscle cramps, and a prolonged QT on ECG. His ionised calcium is 0.85 mmol/L (normal 1.1-1.3). What is the cause?

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Correct answer: C — Citrate toxicity causing hypocalcaemia

Citrate in stored blood products chelates ionised calcium. Massive transfusion overwhelms hepatic citrate metabolism → functional hypocalcaemia. Symptoms: perioral tingling, muscle cramps, prolonged QT, hypotension, reduced cardiac contractility. Treatment: IV calcium chloride 10% 10 mL or calcium gluconate 10% 30 mL.

Reference: SHOT/BSH – 2023 – Massive transfusion complications