[Malignant hyperthermia as a complication of anesthesia: predisposition is hereditary]

The frequency of malignant hyperthermia in the Netherlands is about 1 in 200,000 anaesthesias. Five times a year, an anaesthetic procedure will be complicated by a malignant hyperthermic metabolic disturbance, which can cause death if treatment is not instituted rapidly, by the administration of dantrolene. Suxamethonium and all the anaesthetic vapours can trigger such a reaction. Malignant hyperthermia patients are healthy patients who have a mutation of the ryanodine receptor gene RYR. Predisposition to malignant hyperthermia is inherited as an autosomal dominant condition. So far a genetic malignant hyperthermia test is not available because of genetic heterogeneity. The in-vitro contracture test in skeletal muscle is currently used as a diagnostic test for malignant hyperthermia. Patients who are likely to be at risk based on a clinical grading score, and family members with at least a 25% chance of inheriting malignant hyperthermia, are eligible for this test.