malignant hyperthermia
Pronunciation: muh-LIG-nant hy-per-THER-mee-uh
A life-threatening pharmacogenetic skeletal muscle disorder triggered by volatile halogenated anesthetic agents or succinylcholine, characterised by uncontrolled hyperthermia, rigidity, and metabolic acidosis.
Full Definition
Malignant hyperthermia (MH) is caused by an autosomal dominant mutation, most commonly in the ryanodine receptor gene (RYR1), leading to uncontrolled calcium release from the sarcoplasmic reticulum when susceptible patients are exposed to triggering agents. In dental anesthesiology, awareness of MH is critical when planning anesthesia for susceptible patients, necessitating an MH-safe technique such as TIVA. Dantrolene is the specific treatment. Editors should note that 'malignant hyperthermia' is always written as two words, never hyphenated, and should not be confused with 'malignant hyperpyrexia' (an older synonym sometimes encountered in British literature) or 'neuroleptic malignant syndrome', which has a different mechanism.
Usage
Usage note: Never hyphenate. The abbreviation MH is acceptable after first use. Distinguish from neuroleptic malignant syndrome (NMS), which is drug-induced and not triggered by volatile agents. In British-authored documents, 'malignant hyperpyrexia' may appear as a synonym but should be flagged for consistency.
In Context
- "A family history of malignant hyperthermia was documented, and a TIVA protocol was implemented to avoid triggering agents." — Pre-anaesthetic assessment form
- "The emergency cart contained two vials of dantrolene sodium as per the malignant hyperthermia preparedness protocol." — Office emergency equipment checklist