A trauma patient receives 14 units of packed red cells and 10 units of fresh frozen plasma during damage-control surgery. Postoperatively he develops perioral tingling, a prolonged corrected QT interval, and a fall in ionized calcium to 0.85 mmol/L. The most appropriate immediate treatment is:

• A Intravenous magnesium sulphate 2 g
• B Oral calcium carbonate and vitamin D replacement
• C Intravenous calcium gluconate with monitoring of ionized calcium ✓
• D Intravenous sodium bicarbonate to correct acidosis

Explanation

Citrate anticoagulant in stored blood chelates ionized calcium, and with massive transfusion the liver may be unable to metabolize the citrate load, producing symptomatic hypocalcaemia with neuromuscular irritability and QT prolongation. Treatment is intravenous calcium gluconate or chloride titrated against serial ionized calcium values. Bicarbonate worsens the problem by lowering ionized calcium further, and oral therapy is far too slow in a shocked, recently operated patient. Magnesium treats torsades from hypomagnesaemia, not citrate toxicity.

Reference: Bailey and Love's Short Practice of Surgery, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.