Last reviewed: November 2017
Last updated: November  2017

Summary

Definition

History and exam

Key diagnostic factors

  • presence of risk factors
  • increased minute ventilation
  • elevated core temperature
  • muscle rigidity

Other diagnostic factors

  • tachycardia
  • decreased urine output
  • excessive sweating with exercise
  • muscle cramps
  • spontaneous episodes of severe muscle stiffness

Risk factors

  • exposure to potent inhalation anaesthetic and/or succinylcholine (suxamethonium)
  • susceptibility to MH
  • previous MH episode
  • positive family history
  • exposure to illicit or designer drugs
  • exertional heat illness

Diagnostic investigations

1st investigations to order

  • discontinuation of inhalation anaesthetic
  • exhaled carbon dioxide, oxygen, and oxygen consumption
  • venous blood gases
  • serum electrolytes
  • serum creatinine
  • therapeutic trial of intravenous dantrolene
  • creatine kinase
  • urinalysis
  • urine myoglobin
  • platelets
  • prothrombin time
Full details

Investigations to consider

  • caffeine halothane contracture test (CHCT)
  • in vitro contracture test (IVCT)
  • genetic testing
  • screen for muscle enzyme deficiencies
Full details

Treatment algorithm

Contributors

Authors VIEW ALL

Assistant Professor

Department of Anesthesiology

University of Colorado

Aurora

CO

Disclosures

LM declares that she has no competing interests.

Professor

Department of Anesthesiology

University of Pittsburgh School of Medicine

Pittsburgh

PA

Disclosures

BWB has been reimbursed by the not-for-profit sponsor of the North American MH Registry (NAMHR), the Malignant Hyperthermia Association of the United States (MHAUS) for attending meetings related to the management of the NAMHR. For the past 16 years, BWB received grants from MHAUS to maintain the NAMHR. BWB has given lectures and prepared educational materials for her previous employer, the Department of Anesthesiology in the University of Pittsburgh. As of 1 July, 2016, BWB retired from that employment. BWB has published papers and prepared educational materials for MHAUS, with the help of other volunteers for MHAUS. BWB sponsored LM for an award granted by the American Society of Anesthesiologists. This award allowed LM to travel to several medical centers that were active in the diagnosis of MH, as well as to the NAMHR to improve her understanding of this syndrome. This is part of BWB's mentoring of younger anesthesiologists. BWB is also an author of a number of references cited in this topic.

Peer reviewers VIEW ALL

Director

Department of Medical Education and Clinical Research

Saint Barnabas Medical Center

Livingstone

NJ

Disclosures

HR declares that he has no competing interests.

Professor of Anesthesia

University of Leeds

Academic Unit of Anesthesia

St James's University Hospital

Leeds

UK

Disclosures

PH is an author of a number of references cited in this monograph.

Associate Professor

Perioperative Patient Safety

Department of Biomedicine

University Hospital Basel

Basel

Switzerland

Disclosures

TG declares that he has no competing interests.

Professor and Chairman

Department of Anesthesiology

Wake Forest University School of Medicine

Winston-Salem

NC

Disclosures

JT is an author of a number of references cited in this monograph.

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