[Two pediatric cases of malignant hyperthermia caused by sevoflurane]

We experienced two cases of malignant hyperthermia (MH) triggered by sevoflurane. Case 1 was a six-year-old girl, 15.8 kg, undergoing strabismus repair. She had flat back, elevated diaphragm and high arched palate. Anesthesia was induced and maintained with sevoflurane and nitrous oxide in oxygen. Her trachea was intubated without the use of muscle relaxant. Thirty minutes after the induction of anesthesia, ETco2 was over 60 mmHg despite hyperventilation. Muscle rigidity of legs and the rise in temperature were noted. MH was diagnosed and dantrolene i.v. was administered. Her maximum esophageal temperature was 40.2 degrees C. ETco2 and temperature returned to baseline values after dantrolene administration. Creatine phosphokinase (CK) level was 252 U.l-1 preoperatively, and 1690 U.l-1 next day. Case 2 was a year-and-9-month-old boy undergoing accessory ear resection. Anesthesia was induced with sevoflurane and nitrous oxide in oxygen. His trachea was intubated with an aid of vecuronium. Forty minutes after administration of sevoflurane his temperature rose to 38.6 degrees C with heart rate 191 bpm and Spo2 93%, and muscle rigidity of legs. MH was diagnosed and dantrolene was administered. His highest temperature was 39.3 degrees C and was reduced promptly after dantrolene. Postoperatively he was noted to have downslanting palpebral fissures, micrognathia, low set ears, and a single crease of the fifth finger and diagnosed as King syndrome which is reported to have association with MH. Both patients had no history of anesthesia nor abnormal family history. Both of them were rescued with dantrolene and recovered without sequelae.