Malignant Hyperthermia Questions and Answers;(perfect guide for your final)

Malignant Hyperthermia - Genetic disorder Affects between 10,000 and 50,000 individuals. Risk of potentially life-threate Onset - In operating room: -tachypnea (rapid breathing) -low plasma [o2] -high plasma [co2] -tachycardia (rapid heart rate) -hyperthermia (rising body temp) can be as rapid as 1 degree every 5 mins. -rigidity, sweating and dramatic swings in blood pressure. Onset usually during anesthesia, but can occur several hours later. Untreated - Pt develops respiratory and lactic acidosis, muscle rigidity, and a breakdown of muscle tissue that leads to the release of K+ and thus profound hyperkalemia. Progressively sever hypermetabolic state in muscle tissue. Current hypothesis - Due to major features - hyperhemia, muscle rigidity and an increased metabolic rate - early investigators suggest MH is a disease of abnormal regulation of muscle contraction. Uncontrolled muscle contraction causes excessive ATP hydrolysis to provide energy for contraction. The increased rate of ATP hydrolysis leads to an increased metabolic rate as muscle tries to replenish and to sustain its ATP stores. Hyperthemia developes because of the heat liberated by the hydrolysis of ATP. Possibility that MH results from an abnormality in the Ca2+ release channel in the SR membrane. Inheritance - Follows a mendelian autosomal dominant pattern. Linked to abnormalities in gene (RYR1) encoding the Ca2+-release channel (ryanodine receptor). Or abnormalities along excitation-contraction cascade can result in abnormal regulation of muscle contraction.Swine - Incidence of MH is high. Episodes are triggered by a variety of physical and environmental stresses. Significant economic importance in view of the potential loss from fatal episodes and the devaluation of meat as a result of muscle destruction during nonfatal episodes.