Malignant hyperthermia 2020: Guideline from the Association of Anaesthetists

Anaesthesia. 2021 May;76(5):655-664. doi: 10.1111/anae.15317. Epub 2021 Jan 5.


Malignant hyperthermia is defined in the International Classification of Diseases as a progressive life-threatening hyperthermic reaction occurring during general anaesthesia. Malignant hyperthermia has an underlying genetic basis, and genetically susceptible individuals are at risk of developing malignant hyperthermia if they are exposed to any of the potent inhalational anaesthetics or suxamethonium. It can also be described as a malignant hypermetabolic syndrome. There are no specific clinical features of malignant hyperthermia and the condition may prove fatal unless it is recognised in its early stages and treatment is promptly and aggressively implemented. The Association of Anaesthetists has previously produced crisis management guidelines intended to be displayed in all anaesthetic rooms as an aide memoire should a malignant hyperthermia reaction occur. The last iteration was produced in 2011 and since then there have been some developments requiring an update. In these guidelines we will provide background information that has been used in updating the crisis management recommendations but will also provide more detailed guidance on the clinical diagnosis of malignant hyperthermia. The scope of these guidelines is extended to include practical guidance for anaesthetists dealing with a case of suspected malignant hyperthermia once the acute reaction has been reversed. This includes information on care and monitoring during and after the event; appropriate equipment and resuscitative measures within the operating theatre and ICU; the importance of communication and teamwork; guidance on counselling of the patient and their family; and how to make a referral of the patient for confirmation of the diagnosis. We also review which patients presenting for surgery may be at increased risk of developing malignant hyperthermia under anaesthesia and what precautions should be taken during the peri-operative management of the patients.

Keywords: activated charcoal filters; dantrolene; malignant hyperthermia: associated disorders; malignant hyperthermia: peri-operative management; malignant hyperthermia: signs.

Publication types

  • Practice Guideline

MeSH terms

  • Acidosis / drug therapy
  • Acidosis / etiology
  • Body Temperature
  • Calcium / administration & dosage
  • Carbon Dioxide / analysis
  • Compartment Syndromes / drug therapy
  • Compartment Syndromes / etiology
  • Dantrolene / therapeutic use*
  • Disseminated Intravascular Coagulation / etiology
  • Disseminated Intravascular Coagulation / therapy
  • Heart Rate
  • Humans
  • Hyperkalemia / drug therapy
  • Hyperkalemia / etiology
  • Malignant Hyperthermia / complications
  • Malignant Hyperthermia / diagnosis
  • Malignant Hyperthermia / drug therapy*
  • Muscle Relaxants, Central / therapeutic use*
  • Myoglobinuria / drug therapy
  • Myoglobinuria / etiology
  • Pulmonary Ventilation
  • Risk Factors
  • Sodium Bicarbonate / administration & dosage


  • Muscle Relaxants, Central
  • Carbon Dioxide
  • Sodium Bicarbonate
  • Dantrolene
  • Calcium