Malignant hyperthermia: experience in the prospective management of eight children.

Malignant hyperthermia (MH) is a seemingly rare genetic myopathy. Hypermetabolic crisis accompanied by a rise in body temperature to as high as 44 degrees C, is its hallmark. Malignant hyperthermia is usually triggered by potent inhalation anesthetics and/or depolarizing muscle relaxants. Because of the extraordinary incidence of death in patients who are at risk, pediatric surgeons may be reluctant to operate on these patients. Eight such patients were referred to the Pediatric Surgery Service and the UCLA Malignant Hyperthermia Center following pediatric surgical procedures aborted for first episodes of malignant hyperthermia (five) or for a strong family history of malignant hyperthermia (three). They were anesthetized with nitrous oxide, barbiturates, opiates, tranquilizers, and nondepolarizing muscle relaxants. The patients were not treated prophylactically with dantrolene. Cardiac monitoring, end-tidal PCO2, and rectal temperatures were monitored. After completion of their pediatric surgical procedures, all eight patients had a vastus lateralis muscle biopsy performed and subsequent caffeine/halothane contracture studies completed. The contracture study result was positive in all patients studied. No anesthetic or surgical complications were encountered. This study shows that patients at risk for developing MH crisis can have pediatric surgical procedures performed safely with appropriately selected general anesthesia.