Management of Malignant Hyperthermia (MH)
Malignant hyperthermia (MH) is a rare, but life-threatening disorder, it is inherited in an autosomal dominant pattern. A potentially lethal hypermetabolic syndrome that may lead to metabolic crisis of skeletal muscle in susceptible individuals following exposure to triggering agents such as volatile anesthetics agents (halothane, enflurane, isoflurane, sevoflurane, and desflurane) or depolarizing muscle relaxants such as suxamethonium(1) . in the course of excitation–contraction coupling, acetylcholine evokes an action ability on the neuromuscular endplate. This action potential is propagated to the transverse tubule, inflicting displacement of the rate on the dihydropyridine receptor. A conformational change on the voltage-gated dihydropyridine receptor is directly transmitted to the ryanodine receptor subtype 1 (RYR1) at the sarcoplasmic reticulum, which responds by opening a big ion channel, allows launch of calcium from the sarcoplasmic reticulum into the cytosol, leading to muscle contraction by initiating cross-linking of myofilaments
Malignant hyperthermia is a potentially fatal genetic defect characterized by disturbance of calcium level in skeletal muscle. Volatile anesthetics and/or the depolarizing muscle relaxant succinylcholine may trigger this hyper-metabolic muscular syndrome due to uncontrolled sarcoplasmic Ca release via functionally altered Ca release receptors, leading to tachycardia, muscular rigidity, hypoxemia, hypercapnia, acidosis, hyperkalemia, and hyperthermia in susceptible individuals. Survival of affected patients depends crucially on the early recognition of symptoms, and characteristic of MH, and immediate action on the part of the presenting anesthesiologist. Since the clinical presentation of malignant hyperthermia is highly variable, the present study includes 3 cases of MH and highlights the timely identification of symptoms for rescuing the patient. In the first case the patient did not survive due to the late noticing of the disorder, for the second case, the patient was treated and managed. lastly, the third case the treatment was unavailable therefore the patient could not be managed. Clinical symptoms of malignant hyperthermia, and current therapeutic guidelines, as well as adequate management of anesthesia in patients susceptible to malignant hyperthermia, are discussed in this report.