malignant hyperthermia syndrome


malignant hyperthermia syndrome

Malignant hyperpyrexia An AD condition–of variable penetration in which the individual when subjected to the anesthetic–halothane, diethyl-ether, cyclopropane, enflurane and certain psychotropics, develops a potentially fatal–up to 70% mortality in acute episodes, occurring in 1/15,000 administrations of anesthesia in children, 1/50-100,000 adults;1⁄2 of cases had not been previously sensitive to anesthesia; anesthetized Pts may develop high fever and muscle rigidity with rhabdomyolysis, release of myoglobin, renal damage and acute renal failure Clinical Tachycardia, tachypnea, cyanosis, labile BP, muscle rigidity, rapid and marked hyperpyrexia, acidotic, hyperkalemic, possibly DIC, renal failure; similar reactions may be evoked in these subjects by warm weather, exercise, emotional stress or without known environmental cues and are initiated by muscular hypermetabolism, due to an idiopathic ↑ in sarcoplasmic calcium occurring under general anesthesia Diagnosis Muscle contraction test with halothane or caffeine challenge Treatment Hypothermia, hydration, sodium bicarbonate infusion, mechanical hyperventilation, diuretics to ↑ urine flow, dantrolene–an agent which blocks excitation-contraction coupling between T tubules and sarcoplasmic reticulum