Search

alignant hyperthermia (MH) was first identified in the 1960s when a patient with a strong family history of anesthetic complications demonstrated increased body temperature, a rapid heart rate, and decreased blood pressure after induction of anesthesia. Soon after this incident, clinicians realized that MH is a hypermetabolic state occurring within skeletal muscle cells that is often triggered by administration of common general anesthetics, such as halothane, isoflurane, sevoflurane, desflurane, or enflurane, alone or in combination with succinylcholine, a depolarizing muscle relaxant and neuromuscular blocker. Emotional stress, trauma, or strenuous exercise also can trigger MH. During an MH event, a biochemical chain reaction occurs that is often characterized first by an unexpected rise in end-tidal carbon dioxide (ETCO2) and muscle rigidity. 1,3-5 Characteristics of MH include hypercarbia, hypoxia, metabolic and respiratory acidosis, tachypnea, dysrhythmias, and an increase in body temperature. Although a temperature increase is the sine qua non of MH, this sign may be missed early in the course of the reaction because of the decrease in temperature that often accompanies anesthesia and surgery. Therefore, an increase in body temperature, which can exceed 43.3 C [109.9 F]), is often a later sign of an MH event. This rise in body temperature can increase