malignant hyperthermia (MH), a rare genetic hypermetabolic condition affecting skeletal muscle occurring in affected people exposed to all halogenated inhalation anesthetics and succinylcholine. It is a life-threatening emergency and must be treated immediately. Compare neuroleptic malignant syndrome. ▪ OBSERVATIONS: MH is characterized by muscle rigidity, rapid heart rate, high body temperature, muscle breakdown, and increased acid content. ▪ INTERVENTIONS: Treatment includes discontinuation of the inhalational anesthetic; the administration of dantrolene sodium (Ryanodex®); administration of 100% oxygen; cooling; cessation of surgery; and correction of acidosis and hyperkalemia. ▪ PATIENT CARE CONSIDERATIONS: Patients susceptible to malignant hyperthermia must be informed of the condition and susceptible relatives screened. The family is referred to the Malignant Hyperthermia Registry of the Malignant Hyperthermia Association of the United States (MHAUS). Individuals with confirmed malignant hyperthermia should wear a medical alert wristband.
