Influence of salbutamol on the in vitro muscle response to caffeine and halothane in malignant hyperthermia

In vitro contracture tests for susceptibility to malignant hyperthermia (MH) were performed with halothane and caffeine in 34 patients, according to the protocol of the European MH Group. Additional halothane and caffeine tests were performed in the presence of salbutamol 50 μg/I. Contractures after exposure to halothane were seen only in MH-susceptible (MHS) patients (n= 16), and were not changed by salbutamol. Salbutamol did not influence the caffeine dose-response curves in any of the groups (n=14 in the MH-non-susceptible (MHN) group). The caffeine threshold concentration was significantly increased by salbutamol in the MHS group.