Malignant hyperthermia in the otology patient: the UCLA experience

Malignant hyperthermia 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 inhalational anesthetics and/or depolarizing muscle relaxants. Because of the extraordinary risk of death in patients who are at risk, otologists may be reluctant to operate on these patients. Seven such patients were referred to the Section of Otology, Neurotology, and Skull Base Surgery and the UCLA Malignant Hyperthermia Center Following first episodes of malignant hyperthermia or with a strong family history of malignant hyperthermia for anesthetic and surgical management. 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 PC02, and rectal temperatures were followed. All seven patients had a vastus lateralis muscle biopsy performed and subsequent caffeine/halothane contracture studies completed. The contracture study was positive in six of the seven patients studied. No anesthetic or surgical complications were encountered. This study demonstrates that patients at risk of developing malignant hyperthermia crisis can have otologic surgical procedures performed safely while undergoing appropriately selected general anesthesia.