Malignant Hyperthermia

Malignant hyperthermia is a rare, life-threatening reaction that occurs in genetically susceptible individuals when they are exposed to certain general anesthetic gases or the muscle relaxant succinylcholine. It causes a rapid, uncontrolled rise in body temperature, muscle rigidity, a fast heart rate and rapid breakdown of muscle tissue, driven by abnormal calcium release inside muscle cells, most often linked to mutations in the RYR1 gene. Without prompt treatment it can be fatal, but it is managed effectively with the drug dantrolene, which blocks the abnormal calcium release, along with cooling and supportive care. Because it is inherited, family members of an affected person are often advised to undergo testing before undergoing general anesthesia themselves.