[Malignant Hyperthermia - Update on Pathophysiology, Diagnostics and Treatment]

Malignant hyperthermia (MH) is a rare, heterogenic syndrome leading to potentially life-threatening skeletal muscle hypermetabolism following exposure to inhalational anesthetics and succinylcholine. In more than 50% of affected individuals a pathogenic variant in the RYR1 gene coding for the sarcoplasmic reticulum calcium channel is responsible for the underlying pathology of uncontrolled calcium liberation. While the genetic prevalence of MH is as high as 1 : 2750, the incidence of clinical MH reactions is considerably lower, suggesting a dominant pattern of inheritance with incomplete penetrance. During acute MH crisis presenting with characteristic symptoms like hypercarbia, tachycardia, acidosis, hyperthermia, generalized muscular rigidity and rhabdomyolysis, discontinuation of triggering agents and immediate treatment with dantrolene 2.5 mg/kg are vital therapeutic interventions to control the reaction. A predisposition to MH should be investigated in patients following a suspected MH crisis, in relatives from MH-families, after exertional or unexplained perioperative rhabdomyolysis and in patients with idiopathic hyper-CK-aemia. According to recent European guidelines, initial DNA screening is an alternative to muscle biopsy and in-vitro contracture testing, although in cases where no diagnostic variants are found, only contracture testing can safely exclude predisposition to MH.