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What is malignant hyperthermia (MH)?
MH is a rare but potentially deadly hypermetabolic crisis that typically occurs as a complication of general anesthesia.¹

Signs of MH may arise at any time during anesthesia or the early postoperative period.¹

This condition results from hypermetabolism in skeletal muscle, probably due to the uncontrolled intracellular release of calcium from the sarcoplasmic reticulum.¹
Who is susceptible?

Who is susceptible?

In almost all cases, patients who are susceptible to MH have a defective calcium channel on the sarcoplasmic reticulum of skeletal muscle cells.¹

This defect, which is inherited as an autosomal dominant trait, has been linked to several different gene mutations.¹ The presence of these mutations can be detected only by exposure to the triggering anesthetic or by specific diagnostic testing.¹

An episode of MH can be triggered by any inhalation anesthetic except nitrous oxide; it can also be triggered by the depolarizing muscle relaxant succinylcholine (suxamethonium).¹

Note that MH has occurred in patients who had previously been exposed to the same anesthetic agents without incident.¹


Testing for MH

The gold standard for determining susceptibility to MH is the caffeine-halothane contracture test, which requires a biopsy of skeletal muscle.²

Genetic tests for susceptibility to MH are also being developed.²

Can MH be prevented?

Prevention of MH involves avoidance of the triggering anesthetic agents in patients with a personal or family history of MH.

Dantrolene sodium for injection can be used preoperatively, and sometimes postoperatively, to prevent or attenuate the development of clinical and laboratory signs of MH in individuals judged to be susceptible to MH.³
Timely treatment

Early recognition and prompt treatment of an MH crisis are essential for the patient’s survival.4

Please see full prescribing information for Revonto.

  1. Rosenberg H, Davis M, James D, et al. Malignant hyperthermia. Orphanet J Rare Dis. 2007;2:21.
  2. Litman RS, Rosenberg H. hyperthermia: update on susceptibility testing. JAMA. 2005;293(23):2918-2924.
  3. Dantrolene sodium for injection [prescribing information]. Louisville, KY: USWM, LLC; 2020.
  4. Glahn KP, Ellis FR, Halsall PJ, et al. Recognizing and managing a malignant hyperthermia crisis: guidelines from the European Malignant Hyperthermia Group. Br J Anaesth. 2010;105(4):417-420.

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