Adverse Metabolic/Muscular Reaction to Anesthesia Reports (AMRAs) received after January 1, 2007 and before December 31, 2013 in the North American Malignant Hyperthermia Registry of the Malignant Hyperthermia Association of the United States were examined with the goal of describing any changes in the administration of dantrolene, complications associated with dantrolene or with the Malignant Hyperthermia (MH) episode itself that might contribute to increased morbidity. Greater age of the patient, longer time from the
beginning of the anesthetic to the first sign of MH and longer time from the first sign of MH to the administration of dantrolene were all found to be associated with increased risk of complications due to MH. There was no significant change in the side effect profile of dantrolene from the previous report of AMRAs prior to 2007. Patients in whom Pulmonary Edema (PE) was reported received about twice as much intravenous fluid during the initial treatment of MH than did those in whom PE was not reported.