Malignant Hyperthermia

If you’re unaware that you have malignant hyperthermia susceptibility and undergo anesthesia with a triggering anesthetic, you and your anesthesiologist won’t know you have it until you have a reaction.

Whenever you or anyone undergoes anesthesia, the anesthesiologist or nurse anesthetist carefully monitors your vital signs and health during your procedure and after. If you have malignant hyperthermia, they’ll recognize it through certain abnormal vital signs and reactions, including:

• Unexplained increase in heart rate.
• Rapid increase in temperature.
• Unexplained increase in carbon dioxide.
• Muscle rigidity.

Early detection of these changes is what anesthesia providers are trained to look for so they can respond to this emergency quickly. The more rapid the diagnosis, the faster the reaction can be treated and corrected.

Diagnosis of malignant hyperthermia susceptibility

If you or your healthcare provider think you may be susceptible to malignant hyperthermia due to family history, your provider may recommend special tests and procedures to diagnose it, including:

• Caffeine halothane contracture test (CHCT). For this test, a provider takes a muscle biopsy and exposes the live muscle sample to halothane and caffeine to analyze it for a reaction to an anesthesia gas.
• Genetic testing. Genetic testing can reveal mutations in RYR1, STAC3 and CACNA1S locations on DNA. There are over 45 mutations that are recognized as diagnostic for malignant hyperthermia.

Testing for malignant hyperthermia susceptibility can be expensive and is only available in certain laboratories — CHCT testing is only available at four locations in the United States. Because of this, if you need emergency surgery and have a close relative who has had an episode of malignant hyperthermia, your anesthesiologists will provide a non-triggering anesthetic.