Hipertermia maligna

Abstract

Carriers of malignant hyperthermia (MH), a subclinical metabolic myopathy, respond differently to the general population in response to triggering agents, such as volatile anesthetics and succinylcholine. Its incidence ranges from 1:10,000 to 1:250,000 anesthesias. Using etiological treatment, the current mortality rate is around 5%. The biochemical, metabolic, and physiological deterioration generally associated with MH is a direct result of a sudden and progressive increase in intracellular calcium in striated muscle cells. This generates a hypermetabolic state, with a rapid increase in body temperature that can lead to a fatal outcome if not diagnosed and treated in time. The genetic factors that determine susceptibility to MH are complex, with the participation of more than one gene. Its clinical symptoms are highly variable, from mild or moderate to fulminant attacks with severe muscle hypermetabolism and rhabdomyolysis. Capnography and pulse oximetry have great clinical diagnostic value. Other early symptoms of an MH attack may include sinus tachycardia, supraventricular or ventricular arrhythmia, and isolated masterean spasm or generalized muscle stiffness. The rise in temperature is a late sign. After an attack, or in possibly susceptible patients, the laboratory diagnosis is made with the in vitro contracture test, in which the contraction of muscle fibers, obtained through a skeletal muscle biopsy, is studied in the presence of halothane or caffeine. In patients known to be susceptible to MH, neuraxial and regional techniques should be preferred if surgery allows it; otherwise, trigger-free anesthetic methods (TIVA) should be available. Management of the MH crisis is based on three main actions: 1) stopping the administration of halogenates; 2) hyperventilation with 100% oxygen, and 3) administration of intravenous dantrolene. RESUmENLa hipertermia maligna (HM) es una miopatía metabólica subclínica, cuyos portadores tienen una respuesta diferente a la población general ante la presencia de un agente desencadenante: anestésicos volátiles y succinilcolina. Su incidencia tiene rangos entre 1:10.000 a 1:250.000 anestesias. Su mortalidad actual usando tratamiento etiológico es de 5%. El deterioro bioquímico, metabólico y fisiológico asociado clásicamente al cuadro de HM es el resultado directo de un aumento súbito y progresivo del calcio intracelular de las células musculares estriadas, que genera un estado hipermetabólico, calor y un rápido aumento de la temperatura corporal, que puede llevar a un desenlace fatal si no se diagnostica y se trata a tiempo. Su herencia es compli-