Fatal Fluctuation of Serum Potassium Level during Barbiturate Coma Therapy

Abstract

Severe hypokalemia and rebound hyperkalemia is rare side effect of barbiturate. The authors report an experience of lifethreatening fluctuation of serum potassium level from barbiturate coma therapy in severe brain injury patient. A 54-yearold man falling from a golf-cart suffered multiple hemorrhagic contusion and traumatic subarachnoid hemorrhage. He was treated with barbiturate coma therapy conservatively for 20 hours. One hour after cessation of barbiturate infusion, cardiac arrest happened. Meanwhile serum potassium level was 1.5 mmollL. 24 hours after discontinuation of barbiturate, another asystole occurred, and the serum potassium level was 8.5 mmol1L. This rare side effect of barbiturate is mediated by transcellular shift of potassium. Clinicians should monitor closely the electrolyte balance during barbiturate infusion, and possibility of rebound hyperkalemia after the cessation must be borne in mind.