Malignant hyperthermia (MH) is a pharmacogenetic disease that manifests itself as a hypermetabolic response of skeletal musculature, in genetically susceptible patients, with the inhalation of volatile halogenated anesthetics, depolarizing neuromuscular relaxants such and, rarely, physical stressors such as intense exercise and heat stroke.

Risk factors to present this disease are:

• An adverse reaction to general anesthesia manifested as an unexplained increase in carbon, dioxide production, tachycardia, temperature rise, muscle. stiffness, rhabdomyolysis, disseminated intravascular coagulation or death, or both. During anesthesia or within 60 minutes of treatment discontinuation.
• Family history of unexplained perioperative death.
• Postoperative rhabdomyolysis after clinical exclusion of other myopathies.
• Stress rhabdomyolysis, recurrent or persistent rhabdomyolysis increased serum creatine kinase concentration where no cause has been identified after neurological study (idiopathic hyperCKemia).
• Heat stroke by effort that requires hospital admission, where known predisposing factors have been excluded.
• Other myopaties Extreme physical activity, as well as environments with high temperatures favor the appearance of ischemia, anoxia and release of calcium from the sarcoplasmic reticulum, thus increasing the risk of developing MH.

There are also other infrequent diseases in which there is a ryanodine canalopathy by a mechanism similar to that seen in MH, but in cells of tissues other than skeletal striated muscle; as well as some drugs and other rare diseases that may be related to MH.

Despite the rarity of MH and given the severity of the disease clinic, it is mandatory to explore possible risks in patients with hypermetabolic response of skeletal musculature due to rare or trigger diseases (medications, drugs of abuse, exercise, extreme heat, others) whose MH risk is not defined.

Although the standard method for the diagnosis of MH is the in vitro test for halothane caffeine contraction (IVCT), it has been described that B lymphocytes of patients with MH have metabolic alterations. Alto, there are about 50 genetic variants associated with MH that have been described.