title: Safety of general anesthesia in patients previously tested negative for malignant hyperthermia susceptibility.
abstract: Anesthetic management and outcome were examined in patients with negative in vitro contracture tests for malignant hyperthermia (MH). Contracture testing was performed in a standardized fashion using 3% halothane alone and incremental doses of caffeine alone. Medical records were examined for 54 anesthetic exposures in 42 MH(-) patients who had received anesthesia since their MH testing. Sixteen patients received anesthesia with known MH triggering agents on 23 occasions, all without incident. In six MH(-) patients with previous masseter muscle rigidity, no adverse reactions occurred in response to volatile anesthetic agents. Succinylcholine was avoided in these patients. Eleven MH(-) patients were managed as if MH-susceptible, although it was known that these patients had tested MH(-). Two of these patients also receive prophylactic iv dantrolene. These results suggest that "triggering" anesthetic agents may be safely administered to patients who test MH(-) by in vitro contracture testing. However, until the anesthetic experience of larger numbers of MH(-) patients is known, these results should be interpreted cautiously.
authors.affiliation: Department of Anesthesiology, Hahnemann University, Philadelphia, Pennsylvania 19102.
authors.forename: G C
authors.initials: GC
authors.lastname: Allen
authors.forename: H
authors.initials: H
authors.lastname: Rosenberg
authors.forename: J E
authors.initials: JE
authors.lastname: Fletcher
mesh_terms: D000768:Anesthesia, General / Q000009:adverse effects*; D002110:Caffeine; D003286:Contracture / Q000139:chemically induced; D004198:Disease Susceptibility; D006221:Halothane; D006801:Humans; D008305:Malignant Hyperthermia / Q000175:diagnosis / Q000209:etiology*
chemical_list: D002110:Caffeine; D006221:Halothane