Malignant Hyperthermia Management

Introduction to Malignant Hyperthermia

Patients with a history of malignant hyperthermia (MH) must not be exposed to inhalational anesthetics or succinylcholine, regardless of whether they previously tolerated these agents without incident, as recommended by the European Malignant Hyperthermia Group and the Association of Anaesthetists 1, 2
Triggering agents for MH include all potent inhalation anesthetics (such as desflurane, sevoflurane, isoflurane, halothane) and succinylcholine, according to the European Malignant Hyperthermia Group 1
The European Malignant Hyperthermia Group provides a strong recommendation that "only trigger-free anesthesia should be used in all MH-susceptible patients" 1
The Association of Anaesthetists guidelines clearly state that "patients at increased risk of developing MH must not be exposed to potent inhalational anesthetics or suxamethonium" 2

Regional or local anesthesia is preferred when appropriate for patients with a history of MH, as recommended by the European Malignant Hyperthermia Group and the Association of Anaesthetists 1, 2
Total intravenous anesthesia (TIVA) is the recommended approach when general anesthesia is required for patients with a history of MH, according to the European Malignant Hyperthermia Group and the Association of Anaesthetists 1, 2
The American Society of Anesthesiologists is not mentioned in this article, however, the European Malignant Hyperthermia Group and the Association of Anaesthetists recommend avoiding all volatile anesthetics and succinylcholine, and following established guidelines for safe TIVA practice 1, 2

When preparing for an MH-susceptible patient, the anesthetic machine must be properly prepared by removing vaporizers from the anesthetic workstation, changing the anesthetic breathing circuit and soda lime canister, and flushing the circuit with oxygen or air at maximum flow rate for workstation-specific time, as recommended by the European Malignant Hyperthermia Group 1
An alternative preparation method includes removing vaporizers from the anesthetic workstation, flushing the circuit with oxygen or air at maximum flow rate for 90 seconds, inserting activated charcoal filters (ACFs) on both inspiratory and expiratory limbs, and changing the anesthetic breathing circuit and soda lime canister, according to the European Malignant Hyperthermia Group 1

Even if a patient previously tolerated inhalational anesthetics, the risk of a potentially fatal MH reaction outweighs any benefit of using these agents when safe alternatives exist, as stated by the European Malignant Hyperthermia Group and the Association of Anaesthetists 1, 2
The lowest vapor concentration of volatile anesthetic that can trigger MH in humans remains unknown, making any exposure potentially dangerous, according to the European Malignant Hyperthermia Group 1