Serum and urinary myoglobin following an aborted malignant hyperthermia reaction

A 13-year-old boy presenting for correction of bat ears was anaesthetised with thiopentone and suxamethonium, the administration of which was followed by jaw spasm, poor peripheral perfusion (without cyanosis) and marked tachycardia. The procedure was abandoned, dantrolene and Ringer lactate IL were given intravenously and the patient regained consciousness 1 h later. Levels of serum myoglobin, urinary myoglobin and creatine kinase were followed until they returned to normal. Despite a peak serum myoglobin of 58.000 micrograms.l-1 and peak urinary level of 446,000 micrograms.l-1, no renal impairment occurred. Subsequent testing for susceptibility to malignant hyperthermia proved positive for the patient and four other members of the family.