Dẫn xuất halogen hóa thuốc mê đường hô hấp, chẳng hạn như halothane, và giãn cơ khử cực, chẳng hạn như succinylcholine, là một trong những đại lý tủa phổ biến hơn. Các dấu hiệu của hội chứng này được đặt nội khí quản khó khăn | 894 14 Myopathies Table Causes of myoglobinuria Excessive physical stress Metabolic myopathies cf. Table Myotonias Myositis Infection viral bacterial Muscular dystrophy Ischemic necrosis of muscle Mechanical trauma crushing injury burn status epilepticus Medications and toxic substances alcohol gasoline vapors anesthetic gases succinylcholine illicit drugs hypnotics neuroleptics clofibrate statins snake venom insecticides etc. Malignant hyperthermia see above Malignant neuroleptic syndrome Electrolyte disturbances hypokalemia hypophosphatemia 785 component. The responsible genetic defects are located on chromosomes and . The defect at the former locus causes faulty expression of the ryanodine receptor of the calcium channels of the sarcoplasmic reticulum. A defect at the same locus is the genetic basis of central core myopathy a disorder that predisposes to malignant hyperthermia. This explains why patients with certain kinds of myopathy are at elevated risk of malignant hyperthermia. Clinical Features Most patients are asymptomatic until they undergo general anesthesia and while anesthetized develop an unexpected and potentially lethal hyper- metabolic disorder of muscle. Halogenated inhalational anesthetics such as halothane and depolarizing muscle relaxants such as succinylcholine are among the more common precipitating agents. The hallmarks of this syndrome are difficult intubation tachycardia arrhythmia possible cardiac arrest hyperventilation muscle rigidity and above all extreme hyperthermia. The syndrome is similar in some respects to malignant neuroleptic syndrome p. 307 . Identification of Persons at Risk The best indicator of risk is a positive personal or family history of similar events. Uncomplicated general anesthesia in the past unfortunately does not mean that malignant hyperthermia cannot occur during a subsequent operation under general anesthesia. As mentioned above certain types of myopathy including the .
