Malignant hyperthermia
Last updated 18 Aug 2020
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Malignant hyperthermia is a severe reaction to particular anesthetic drugs that are often used during surgery and other invasive procedures. Specifically, this reaction occurs in response to some anesthetic gases, which are used to block the sensation of pain, either given alone or in combination with a muscle relaxant that is used to temporarily paralyze a person during a surgical procedure. If given these drugs, people at risk of malignant hyperthermia may experience a rapid increase in heart rate and body temperature (hyperthermia), abnormally fast breathing, muscle rigidity, breakdown of muscle fibers (rhabdomyolysis), and increased acid levels in the blood and other tissues (acidosis). Without prompt treatment and cessation of the drugs, the body's reaction can cause multiple organs to be unable to function, including the heart (cardiac arrest) and kidneys (renal failure), and it can cause a blood clotting abnormality called disseminated intravascular coagulation. These complications may be life-threatening. (In medicine, the term malignant refers to conditions that are dangerous to one's health.)
Description
Malignant hyperthermia is a severe reaction to particular anesthetic drugs that are often used during surgery and other invasive procedures. Specifically, this reaction occurs in response to some anesthetic gases, which are used to block the sensation of pain, either given alone or in combination with a muscle relaxant that is used to temporarily paralyze a person during a surgical procedure. If given these drugs, people at risk of malignant hyperthermia may experience a rapid increase in heart rate and body temperature (hyperthermia), abnormally fast breathing, muscle rigidity, breakdown of muscle fibers (rhabdomyolysis), and increased acid levels in the blood and other tissues (acidosis). Without prompt treatment and cessation of the drugs, the body's reaction can cause multiple organs to be unable to function, including the heart (cardiac arrest) and kidneys (renal failure), and it can cause a blood clotting abnormality called disseminated intravascular coagulation. These complications may be life-threatening. (In medicine, the term malignant refers to conditions that are dangerous to one's health.)
People at increased risk of this disorder are said to have malignant hyperthermia susceptibility. Affected individuals may never know they have the condition unless they have a severe reaction to anesthesia during a surgical procedure or they undergo testing (for instance, if susceptibility is suspected because a family member had a severe reaction). Malignant hyperthermia may not occur every time anesthesia is used. Many individuals who develop a severe reaction have previously been exposed to a triggering drug and not had a reaction.
Affected individuals may be at increased risk for "awake" malignant hyperthermia, in which the severe reaction occurs in response to physical activity, often while sick, rather than in reaction to exposure to a triggering drug.
While malignant hyperthermia often occurs in people without other serious medical problems, certain inherited muscle diseases (including central core disease, multiminicore disease, and STAC3 disorder) are associated with malignant hyperthermia susceptibility.
Inheritance patterns
The source lists the following possible inheritance patterns: Autosomal dominant. More than one pattern can apply in different cases.
Related genes
Other names
Anesthesia related hyperthermia
Hyperpyrexia, malignant
Hyperthermia, malignant
Malignant hyperpyrexia
MHS
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Further reading and references
- Malignant hyperthermia; MedlinePlus, National Library of Medicine.
- Ellinas H, Albrecht MA. Malignant Hyperthermia Update. Anesthesiol Clin. 2020 Mar;38(1):165-181. doi: 10.1016/j.anclin.2019.10.010.
- Kraeva N, Sapa A, Dowling JJ, Riazi S. Malignant hyperthermia susceptibility in patients with exertional rhabdomyolysis: a retrospective cohort study and updated systematic review. Can J Anaesth. 2017 Jul;64(7):736-743. doi: 10.1007/s12630-017-0865-5. Epub 2017 Mar 21.
- Litman RS, Rosenberg H. Malignant hyperthermia: update on susceptibility testing. JAMA. 2005 Jun 15;293(23):2918-24. doi: 10.1001/jama.293.23.2918.
- Riazi S, Biesecker LG, Rosenberg H, Dirksen RT. Nonsyndromic Malignant Hyperthermia Susceptibility. 2003 Dec 19 [updated 2025 Aug 7]. In: Adam MP, Bick S, Mirzaa GM, Wallace SE, Amemiya A, editors. GeneReviews(R) [Internet]. Seattle (WA): University of Washington, Seattle; 1993-2026. Available from http://www.ncbi.nlm.nih.gov/books/NBK1146/
- Riazi S, Kraeva N, Hopkins PM. Malignant Hyperthermia in the Post-Genomics Era: New Perspectives on an Old Concept. Anesthesiology. 2018 Jan;128(1):168-180. doi: 10.1097/ALN.0000000000001878.
- Riazi S, Kraeva N, Hopkins PM. Updated guide for the management of malignant hyperthermia. Can J Anaesth. 2018 Jun;65(6):709-721. doi: 10.1007/s12630-018-1108-0. Epub 2018 Mar 29.
- Treves S, Anderson AA, Ducreux S, Divet A, Bleunven C, Grasso C, Paesante S, Zorzato F. Ryanodine receptor 1 mutations, dysregulation of calcium homeostasis and neuromuscular disorders. Neuromuscul Disord. 2005 Oct;15(9-10):577-87. doi: 10.1016/j.nmd.2005.06.008.
- Zaharieva IT, Sarkozy A, Munot P, Manzur A, O'Grady G, Rendu J, Malfatti E, Amthor H, Servais L, Urtizberea JA, Neto OA, Zanoteli E, Donkervoort S, Taylor J, Dixon J, Poke G, Foley AR, Holmes C, Williams G, Holder M, Yum S, Medne L, Quijano-Roy S, Romero NB, Faure J, Feng L, Bastaki L, Davis MR, Phadke R, Sewry CA, Bonnemann CG, Jungbluth H, Bachmann C, Treves S, Muntoni F. STAC3 variants cause a congenital myopathy with distinctive dysmorphic features and malignant hyperthermia susceptibility. Hum Mutat. 2018 Dec;39(12):1980-1994. doi: 10.1002/humu.23635. Epub 2018 Oct 11.
- Zvaritch E, Gillies R, Kraeva N, Richer M, Jungbluth H, Riazi S. Fatal awake malignant hyperthermia episodes in a family with malignant hyperthermia susceptibility: a case series. Can J Anaesth. 2019 May;66(5):540-545. doi: 10.1007/s12630-019-01320-z. Epub 2019 Feb 19.
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