What Is Malignant Hyperthermia?

Malignant hyperthermia is a dangerous reaction in response to a certain dose of anesthetic drugs.1 This reaction can turn out to be fatal sometimes, if not treated emergently and efficiently. It is seen in those persons particularly who suffer from a muscle abnormality that is quite rare. This muscle abnormality is inherited and runs in the family. On rarest of the rare occasions, strenuous physical exercise or even a heat stroke can cause this reaction in a person who suffers from this muscle abnormality.

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How Does Malignant Hyperthermia Occur?

How Does Malignant Hyperthermia Occur?

The persons, who have this inherited muscle abnormality, have a particular protein on the surfaces of the muscles. This protein does not cause any effect on the muscle functioning normally. But once exposed to such triggering drugs as the volatile anesthetics, it can cause this serious reaction known as malignant hyperthermia.

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When a person who has inherited this muscle-abnormality is exposed to these triggering drugs, the calcium that is present in the muscles gets released and the muscles contract and also get rigid at the same moment. In later stages, the body temperature increases dangerously and very dramatically.

As anesthetics, especially the volatile ones are responsible for creating this dangerous reaction in the body, malignant hyperthermia is usually seen to be happening after or during a surgery, once the anesthetic is administered in the body. This may take a few minutes to a few hours. However, apart from surgery, malignant hyperthermia can get triggered at many other places where anesthetics are involved, like a dental set-up, emergency rooms or an intensive care unit (ICU).

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This condition malignant hyperthermia is sometimes seen in persons suffering from muscular dystrophy and other muscle diseases as well that are particularly linked to gene mutations.

Signs And Symptoms Of Malignant Hyperthermia

The signs and symptoms of malignant hyperthermia may consist of one or many of the following symptoms

  • Muscular rigidity and stiffness, especially in the jaw muscles or masseter muscles
  • Severe muscular pain
  • Tachycardia- an increased heart rate 2
  • Tachypnea- an increased respiration rate
  • Increase in an end tidal carbon dioxide etco2 levels
  • Hypotension- extremely low blood pressure
  • Dangerous increase in the body temperature

In some people who suffer from malignant hyperthermia, these symptoms may never be seen, or are seen after multiple exposures to the triggering drugs; and not in the first exposure.

Diagnosis Of Malignant Hyperthermia

Diagnosis an malignant hyperthermia in a normal person can be quite a challenge, as this reaction is triggered only in the presence of anesthetic drugs. Most of the people are hence diagnosed at the time of a surgery or following the surgery. This condition is usually suspected when the person presents with severe muscle rigidity after an exposure to the anesthetics. Muscle rigidity is then followed by tachycardia, tachypnea, etco2 increase and other symptoms which further confirm the diagnosis of malignant hyperthermia.

Treatment Of Malignant Hyperthermia

Once the condition of malignant hyperthermia is diagnosed, emergency treatment must be started in order to avoid further complications.

  • The first and the foremost step is to withdraw the triggering anesthetic
  • Next, surgery must be stopped immediately if that is an option
  • If not, then the anti-dote dantrolene is administered to counteract the effects caused by the triggering drug
  • Dantrolene is the only known anti-dote for malignant hyperthermia 3
  • Dantrolene for malignant hyperthermia acts as a muscle relaxant and arrests the metabolism in muscles
  • It is administered in the veins and is given till the symptoms recede and the person stabilizes
  • It may be required to be continued for a few more days
  • If body temperature rises dangerously, methods to bring it down may be needed, like cooling the body with cooling blankets etc.
  • Ventilation is started
  • Tachycardia and tachypnea are treated accordingly.

Malignant hyperthermia is an extremely dangerous condition that is seen in people suffering from an inherited muscular abnormality. It can prove to be dangerously fatal in absence of a prompt and efficient treatment.

References:  

Also Read:

Pramod Kerkar

Written, Edited or Reviewed By:

, MD,FFARCSI

Pain Assist Inc.

Last Modified On: August 13, 2019

This article does not provide medical advice. See disclaimer

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