Malignant hyperthermia (MH) is a dangerous reaction that is triggered in response to certain anesthetic drugs.1 This can prove to be a fatal condition if left untreated.

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Malignant hyperthermia is seen in persons who suffer from a muscle abnormality that is quite rare. This is a genetically inherited condition and runs in the family. On very rare occasions, a high magnitude physical exercise or even a heat stroke can trigger this reaction in a person suffering from this muscle abnormality.

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How Can You Tell If You Have Malignant Hyperthermia?

  • All patients who receive the triggering agents are kept on a watch for any signs of malignant hyperthermia. It may so happen that the person receiving any of the triggering drugs might not have shown any signs of malignant hyperthermia in their last exposures.
  • It has also happened that those who have developed a malignant hyperthermia during or after a surgery have not had any history of malignant hyperthermia running in their families.

Even if one or two typical signs and symptoms associated with this condition are present, they must not be overlooked, and prompt vigilance must be kept under all circumstances.

A person receiving triggering drugs or under anesthesia should be evaluated for a risk of malignant hyperthermia, especially if any of these signs of malignant hyperthermia are present.

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  • End-tidal carbon dioxide also known as ETCO2 levels increase, and these levels do not come to normal even after increasing the ventilation.2
  • Muscular rigidity especially when a neuromuscular blockade is administered.
  • Increased heart rate also known as tachycardia which is unexplained.
  • Increased respiration rate also known as tachypnea which is unexplained too.
  • Increased potassium (hyperkalemia) related irregular heart rate also known as arrhythmias.
  • Abnormally and dangerously increasing body temperature also known as hyperthermia

Causes of Malignant Hyperthermia

  • Malignant hyperthermia is a genetically inherited condition.1
  • A person suffering from this condition may pass it on to other generations.
  • Men are more commonly seen to be affected by this condition, than women.
  • Even if A person having this condition does not suffer from this condition in the first instance of surgery, he may still remain at a risk in future exposures to anesthetics.
  • In very rare cases, the people present with the symptoms of malignant hyperthermia after a very strenuous or extreme physical activity.

Treatment of Malignant Hyperthermia

After the diagnosis of malignant hyperthermia condition, emergency treatment needs to be started to avoid further complications and treat the condition effectively.

  • Withdraw the triggering anesthetic as immediately as possible.
  • Surgery must be terminated immediately if there is an option to do this.
  • Anti-dote dantrolene is administered to counteract the effects caused by the triggering drug.
  • Dantrolene is the only known anti-dote for this condition.
  • Dantrolene for malignant hyperthermia works as a muscle relaxant and stops the metabolism in muscles.
  • The method of administration of this drug is intravenous and it is given till the symptoms subside and the person stabilizes.
  • It may be required to be continued for a few more days.
  • If body temperature increases to dangerous levels, 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.

Prevention of Malignant Hyperthermia

Prevention of malignant hyperthermia may not be possible in all cases that are scheduled for a surgery as it is practically not possible to check each and every case of surgery to test for the presence of this condition. However, some of the cases scheduled for a surgery must be checked, especially those presenting with the following factors

  • If the person has a history of malignant hyperthermia running in his family
  • If there is a history of hyperthermia after carrying out extreme physical exercise
  • If the person suffers from any muscle abnormalities that are genetic in condition

Malignant hyperthermia is a very dangerous, genetically inherited condition. If not diagnosed promptly and due to lack of an efficient treatment, it may prove to be fatal.

References:  

Also Read:

Pramod Kerkar

Written, Edited or Reviewed By:

, MD,FFARCSI

Pain Assist Inc.

Last Modified On: July 31, 2019

This article does not provide medical advice. See disclaimer

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