Neurosurgery in the malignant hyperthermia-susceptible patient

Abstract

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 inhaled anesthetics or depolarizing muscle relaxants. Because of the extraordinary risk of death in patients who are susceptible, neurosurgeons may be reluctant to operate on these patients. Three such patients were referred to the Neurosurgery Service and the UCLA Malignant Hyperthermia Center after neurosurgical procedures aborted for first episodes of malignant hyperthermia. 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 followed. After completion of the neurosurgical procedures, all three patients had a vastus lateralis muscle biopsy and subsequent caffeine/halothane contracture studies. The contracture study was positive in all patients. No anesthetic or surgical complication was encountered. This study demonstrates that neurosurgical procedures can be performed safely in patients at risk of developing malignant hyperthermia while they undergo appropriately selected general anesthesia.