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Malignant Hyperthermia
Pathophysiology of Malignant Hyperthermia
Malignant hyperthermia affects about 1/20,000 people. Susceptibility is inherited, with autosomal dominant inheritance and variable penetrance. Most often, the causative mutation affects the ryanodine receptor of skeletal muscle; however,>22 other causative mutations have been identified. The mechanism may involve anesthetic-induced potentiation of calcium (Ca) exit from the sarcoplasmic reticulum of skeletal muscle in susceptible patients. As a result, Ca-induced biochemical reactions are accelerated, causing severe muscle contractions and elevation of the metabolic rate, resulting in respiratory and metabolic acidosis. In response to the acidosis, patients breathing spontaneously develop tachypnea that only partially compensates. Hyperkalemia , respiratory and metabolic acidosis, 