Xenon does not induce contracture in human malignant hyperthermia muscle

Xenon has many characteristics of an ideal anaesthetic agent. It is not kno wn whether xenon is a safe alternative to the potent inhalational anaesthet ics in patients susceptible to malignant hyperthermia (MH). We investigated the effect of xenon, halothane and caffeine on muscle specimens of 31 indi viduals, referred to the MH Unit of the University of Ulm, and performed ge netic epidemiology. Thirteen individuals were classified as MH susceptible and 18 as MH negative. Xenon 70% did not cause an increase in baseline tens ion of any MH-susceptible muscle specimen in contrast to halothane and caff eine. The evoked twitch response increased transiently in Mi-I-susceptible and normal specimens indicating a mechanism independent of MH susceptibilit y. These results suggest that xenon, in concentrations up to 70% may be a s afe anaesthetic for MH-susceptible patients.