Malignant hyperthermia

Abstract 

Malignant hyperthermia (MH) is a pharmacogenetic disorder. Indeed, it was among the first group of pharmacogenetic conditions reviewed in the anaesthetic literature. Most patients who are susceptible to MH have no overt manifestations of the condition until they are exposed to the triggering drugs, which comprise the potent inhalational anaesthetics and suxamethonium. There is currently no valid population screening test for MH and the key to avoiding mortality or chronic morbidity rests with anaesthetists recognizing the early features of a developing MH reaction and then intervening appropriately. There are no clinical pathognomonic features of MH but an understanding of the cellular and systemic events underlying the reaction is most useful in making the provisional diagnosis. This article will focus on these pathophysiological mechanisms and the rationale for published management guidelines. As MH is fundamentally a disorder of skeletal muscle calcium regulation it is necessary first to summarize the physiology of skeletal muscle calcium release and reuptake.

Keywords: dantrolene, excitation-contraction coupling, skeletal muscle