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Malignant hyperthermia: Clinical diagnosis and management of acute crisis

Ronald S Litman, DO, FAAP
Section Editor
Stephanie B Jones, MD
Deputy Editor
Marianna Crowley, MD


Malignant hyperthermia (MH) manifests clinically as a hypermetabolic crisis when an MH-susceptible (MHS) individual is exposed to a volatile anesthetic (eg, halothane, isoflurane, enflurane, sevoflurane, desflurane) or succinylcholine [1-5].

This topic will discuss the incidence, pathophysiology, clinical manifestations, and acute management of MH. Susceptibility to MH and administration of anesthesia to MHS patients are discussed elsewhere. (See "Susceptibility to malignant hyperthermia: Evaluation and management".)


The clinical incidence of malignant hyperthermia (MH) for a given population depends upon the prevalence of MH susceptibility and use of triggering anesthetics. (See "Susceptibility to malignant hyperthermia: Evaluation and management", section on 'Prevalence'.)

The incidence of episodes of MH in the general population is estimated as 1:100,000 administered anesthetics [6]. This is probably an underestimate because unrecognized, mild, or atypical reactions occur due to variable penetrance of the inherited trait. Approximately half of patients who develop acute MH have one or two uneventful exposures to triggering agents [7,8].

Epidemiology — MH occurs in all ethnic groups in all parts of the world. Reactions occur more frequently in males than females (2:1) [6,7,9]. Children under 19 years account for 45 to 52 percent of reported events [7,9].


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Literature review current through: Sep 2016. | This topic last updated: Sep 1, 2016.
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