Summary
Definition
History and exam
Key diagnostic factors
- exposure to potent inhalation anesthetic and/or succinylcholine
- susceptibility to malignant hyperthermia (MH)
- previous malignant hyperthermia (MH) episode
- positive family history
- 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 anesthetic and/or succinylcholine
- susceptibility to Malignant hyperthermia (MH)
- previous malignant hyperthermia (MH) episode
- positive family history
- exertional heat illness
Diagnostic tests
1st tests to order
- discontinuation of inhalation anesthetic
- exhaled carbon dioxide, oxygen consumption (inspired-expired oxygen concentration difference)
- venous blood gases
- serum electrolytes
- serum creatinine
- therapeutic trial of intravenous dantrolene
- creatine kinase
- urinalysis
- urine myoglobin
- platelets
- prothrombin time
Tests to consider
- caffeine halothane contracture test (CHCT)
- in vitro contracture test (IVCT)
- genetic testing
- screen for muscle enzyme deficiencies
Treatment algorithm
inhalation anesthetic-induced
exercise- or heat-induced
Contributors
Authors
Christopher M. Edwards, MD
Assistant Professor
Department of Anesthesiology
University of Florida College of Medicine
Gainesville
FL
Disclosures
CME declares that he has no competing interests.
Nikolaus Gravenstein, MD
Professor
Department of Anesthesiology
University of Florida College of Medicine
Gainesville
FL
Disclosures
NG is a medical adviser/consultant for Teleflex, and has co-developed anesthesia patient safety education courses.
Acknowledgements
Christopher M Edwards and Nikolaus Gravenstein would like to gratefully acknowledge Dr Barbara W. Brandom and Dr Lena Mayes, the previous contributors to this topic.
Disclosures
LM declares that she has no competing interests. 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. BWB was the unpaid director of the NAMHR, until Jul 2016. BWB is also an author of a number of references cited in this topic.
Peer reviewers
Henry Rosenberg, MD
Director
Department of Medical Education and Clinical Research
Saint Barnabas Medical Center
Livingstone
NJ
Disclosures
HR declares that he has no competing interests.
Philip Hopkins, MD
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 topic.
Thierry Girard, MD
Associate Professor
Perioperative Patient Safety
Department of Biomedicine
University Hospital Basel
Basel
Switzerland
Disclosures
TG declares that he has no competing interests.
Joseph Tobin, MD, FAAP, FCCM
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 topic.
Peer reviewer acknowledgements
BMJ Best Practice topics are updated on a rolling basis in line with developments in evidence and guidance. The peer reviewers listed here have reviewed the content at least once during the history of the topic.
Disclosures
Peer reviewer affiliations and disclosures pertain to the time of the review.
References
Key articles
Hopkins PM, Girard T, Dalay S, et al. Malignant hyperthermia 2020: guideline from the Association of Anaesthetists. Anaesthesia. 2021 May;76(5):655-64.Full text Abstract
Larach MG, Dirksen SJ, Belani KG, et al; Society for Ambulatory Anesthesiology; Malignant Hyperthermia Association of the United States; Ambulatory Surgery Foundation; Society for Academic Emergency Medicine; National Association of Emergency Medical Technicians. Special article: creation of a guide for the transfer of care of the malignant hyperthermia patient from ambulatory surgery centers to receiving hospital facilities. Anesth Analg. 2012 Jan;114(1):94-100.Full text Abstract
Rüffert H, Bastian B, Bendixen D, et al. Consensus guidelines on perioperative management of malignant hyperthermia suspected or susceptible patients from the European Malignant Hyperthermia Group. Br J Anaesth. 2021 Jan;126(1):120-30.Full text Abstract
European Malignant Hyperthermia Group. Recognising and managing a malignant hyperthermia crisis (v2024). Nov 2024 [internet publication].Full text
Litman RS, Smith VI, Larach MG, et al. Consensus statement of the Malignant Hyperthermia Association of the United States on unresolved clinical questions concerning the management of patients with malignant hyperthermia. Anesth Analg. 2019 Apr;128(4):652-9. Abstract
Reference articles
A full list of sources referenced in this topic is available to users with access to all of BMJ Best Practice.
Differentials
- Nonmalignant hyperthermia rhabdomyolysis
- Muscle disuse atrophy
- Myotonia
More DifferentialsGuidelines
- Recognizing and managing a malignant hyperthermia crisis
- Consensus guidelines on perioperative management of malignant hyperthermia suspected or susceptible patients from the European Malignant Hyperthermia Group
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