[Case of fulminant-malignant hyperthermia occurring on sixth sevoflurane anesthesia]

We report a case of fulminant-malignant hyperthermia that occurred after five uneventful sevoflurane anesthetic procedures. A 7-year-old girl with bronchial asthma was scheduled for closure of palatal fistula under general anesthesia, after five previous uneventful operations under sevoflurane anesthesia. Anesthesia was induced with propofol and vecuronium, and maintained with nitrous oxide, oxygen, and sevoflurane. Body temperature at the beginning of operation was 37.0 degrees C. After 5 hr 10 min, sudden tachycardia and elevations in body temperature and PET(CO2) were noticed. Sevoflurane was discontinued and body surface cooling, hyperventilation with 100% oxygen, and administration of dantrolene sodium 2 mg x kg(-1), furosemide 4 mg, and 7% NaHCO3 solution 10 ml were started on a suspicion of malignant hyperthermia. Body temperature, heart rate, and PET(CO2) reached to 40.1 degrees C, 190 beats x min(-1), and 60 mmHg, respectively, with metabolic acidosis. Twenty minutes after starting dantrolene infusion, these values decreased to 38 degrees C, 150 beats x min(-1), and 39 mmHg, respectively. Laboratory examination showed that serum potassium, CK, AST, ALT, and LDH concentrations and urine myoglobin level were within normal ranges. Clinical symptoms of this patient fulfilled the diagnostic criteria of fulminant-malignant hyperthermia. The trigger drug was considered to be sevoflurane despite the five previous uneventful sevoflurane anesthetic procedures.