Prospective management of malignant hyperthermia in the otolaryngological patient.

Malignant hyperthermia (MH) is a seemingly rare genetic myopathy. Hypermetabolic crises accompanied by a rise in body temperature to as high as 44 degrees C are its hallmark. These are usually triggered by potent inhalation anesthetics or depolarizing muscle relaxants. Because of the extraordinary risk of death in patients who are at risk, otolaryngologists may be reluctant to operate on these patients. Ten such patients undergoing tonsillectomy and adenoidectomy, myringotomy with ventilation tube insertion, and nasal polypectomy were anesthetized with nitrous oxide, barbiturates, opiates, tranquilizers and non-depolarizing muscle relaxants without complication. The patients were not treated prophylactically with dantrolene. Cardiac monitoring and rectal temperatures were followed. All ten patients had vastus lateralis muscle biopsy performed and subsequent caffeine/halothane contracture studies completed. The contracture study was positive in eight out of the patients studied. No anesthetic or surgical complications were encountered. This study demonstrates that patients at risk of developing MH crisis can have otolaryngologic procedures performed safely while undergoing appropriately selected general anesthesia.