3 learning resources available for this topic
Malignant hyperthermia is a rare but life-threatening pharmacogenetic disorder triggered by certain anesthetic agents, particularly succinylcholine and volatile halogenated anesthetics. It presents as a hypermetabolic crisis characterized by hyperthermia, muscle rigidity, tachycardia, and metabolic acidosis during or after anesthesia.
The disorder results from mutations in the ryanodine receptor 1 (RYR1) gene, which controls calcium release from the sarcoplasmic reticulum in skeletal muscle. When triggered by anesthetic agents, these defective calcium channels cause uncontrolled calcium release, leading to sustained muscle contraction, increased oxygen consumption, and excessive heat production.
Early recognition requires monitoring for unexplained tachycardia, increased end-tidal CO2, muscle rigidity, and rising body temperature during anesthesia. Immediate treatment with dantrolene sodium is crucial to prevent complications such as cardiac arrest, rhabdomyolysis, and disseminated intravascular coagulation. Family screening and genetic testing are essential due to the hereditary nature of this condition.