A person with malignant hyperthermia overreacts to certain anesthetic drugs, which can sometimes develop into a serious and medical condition. You can find more information below.
What is malignant hyperthermia?
Malignant hyperthermia is a severe reaction to certain drugs often used during surgery and other invasive procedures. Specifically, this reaction occurs in response to certain anesthetics used to block the sensation of pain and a muscle relaxant used to temporarily paralyze a person during a surgical procedure.
If these drugs are given, people at risk for malignant hyperthermia may experience muscle stiffness, deterioration of muscle fibers, high fever, increased acid levels in the blood and other tissues (acidosis), and a rapid heart rate. Without prompt treatment, the complications of malignant hyperthermia can be life-threatening.
People who are at high risk for this disorder are said to have susceptibility to malignant hyperthermia. Affected individuals may never know they have the condition unless they are tested or have a severe reaction to anesthesia during a surgical procedure. Although this condition usually occurs in people without other serious medical problems, some inherited muscle diseases are associated with susceptibility to malignant hyperthermia.
What is the incidence?
This condition occurs in one of 5,000 to 50,000 cases given anesthetic. Susceptibility to malignant hyperthermia is probably more common but unknown because many people at increased risk for this condition are never exposed to drugs that trigger the reaction.
Causes of malignant hyperthermia
Malignant hyperthermia is more likely to occur in people with muscle cells containing unusual proteins. This causes an abnormal release of calcium in your body when your muscle cells are triggered. Triggers include certain medications, extreme heat, or strenuous physical exercise. Malignant hyperthermia can occur with this release of calcium in the body.
Only some drugs cause this condition. One category of drugs that can cause symptoms are known as volatile anesthetic agents. Among them are the following:
A muscle relaxant called succinylcholine can also cause symptoms.
Who is at risk?
Malignant hyperthermia is an inherited condition. Susceptible people have an altered gene in their cells that can react when exposed to certain drugs.
If a parent or sibling has this condition in the family, the probability of it being seen in others is half. If there is any relative, such as an aunt or uncle, this is 25%. You may not know if a family member has the condition, or if you might, unless they have symptoms during surgery or some other event.
Symptoms of malignant hyperthermia
This may occur during or after administration of certain anesthetics or succinylcholine-type muscle relaxants. You may encounter these drugs in a variety of medical settings, such as hospitals, outpatients, and the dental office. If you have predisposed genes, your body will trigger a reaction when exposed to these drugs.
In the case of malignant hyperthermia, the way your body reacts may be:
- Muscle stiffness , usually first seen in the jaw
- High fever that can reach 43.3 degrees and above
- Faster body metabolism
- fast heartbeat
- rapid breathing
- muscle spasms
- Disruption of muscle fibers
- elevated acid levels in the blood and elsewhere in the body
You may experience these symptoms the first time you are exposed to the drug. It is also possible to experience a reaction after using more than one drug. In some cases, people have experienced these severe symptoms during intense physical activity or extreme heat.
Diagnosis of malignant hyperthermia
Diagnostic methods include muscle biopsies as well as genetic testing. If you have a family member with malignant hyperthermia, you should get tested. Knowing whether you have the gene involved will help you manage future surgical procedures with your doctor.
Testing and diagnosis begin with a visit to your doctor. They will review your family history and determine the best course of action to diagnose the condition.
- blood tests
- urine tests
Your doctor may also order a muscle biopsy to do the caffeine halothane contracture test. This test measures your muscle response to halothane and caffeine.
Malignant hyperthermia treatment
If you are experiencing this condition during a medical event, your doctor will need to work quickly to control the symptoms. Some actions the doctor can take include:
- applying ice packs, cooling blankets, and fans to cool the body
- Using cold isotonic saline via an intravenous drip to lower your body temperature
- Administration of dantrolene
The best way to treat the condition is to avoid exposure to all drugs that cause it, but this can only be done if diagnosed prior to exposure.
Malignant hyperthermia is a serious medical condition. Your doctor can help you manage the condition by avoiding medications that may trigger it during medical procedures. If you have been diagnosed, it is important that you tell your family members and that they also get tested. This will allow them to prepare for the possibility of having the disease.