Home HealthTopics Health Centers Reference Library - ADAM Search NetWellnessSearch   Advanced

ADAM Health Encyclopedia

Malignant hyperthermia

Malignant hyperthermia

Definition

Malignant hyperthermia is an inherited disease that causes a rapid rise in body temperature (fever) and severe muscle contractions when the affected person receives general anesthesia.

This condition is not the same as hyperthermia due to medical emergencies such as heat stroke.

Alternative Names

Hyperthermia - malignant; Hyperpyrexia - malignant

Causes

Malignant hyperthermia is an autosomal dominant trait, meaning it requires only one parent carrying the disease for a child to inherit the condition. It may be associated with muscular diseases such as multiminicore myopathy and central core disease.

One form of malignant hyperthermia is caused by a defect in the ryanodine receptor (RYR1) gene

Symptoms

Malignant hyperthermia is often noted for the first time after a patient is given anesthesia during a surgical procedure.

Symptoms include:

  • Rapid rise in temperature to 105 degrees F or higher
  • Muscle rigidity and stiffness
  • Dark brown urine
  • Muscle ache without obvious exercise to explain sore muscles

Exams and Tests

There may be a family history of malignant hyperthermia or unexplained death during anesthesia.

Tests that may be done include:

Treatment

For an episode of malignant hyperthermia, a cooling blanket can help reduce fever. The use of a drug called dantrolene during episodes of malignant hyperthermia has greatly reduced the number of deaths.

Fluids given by IV and mouth, as well as certain medications, are essential for maintaining kidney function during an acute episode.

Support Groups

Malignant Hyperthermia Association of the United States - www.mhaus.org

Outlook (Prognosis)

Repeated episodes or untreated episodes can cause kidney failure. Untreated episodes can be fatal.

Possible Complications

  • Rhabdomyolysis, a kidney injury caused by excess myoglobin
  • Renal failure
  • Myopathy (weak muscles) or muscular dystrophy
  • Death

When to Contact a Medical Professional

If you know that you or a member of your family has had problems with general anesthesia, or if you know you have a family history of malignant hyperthermia, be sure to notify both the surgeon and the anesthesiologist before having any surgery.

Prevention

If you or anyone in your family has malignant hyperthermia, it is very important to tell your doctor, especially before having surgery with general anesthesia. The use of appropriate anesthetic medication can prevent the complications of malignant hyperthermia during surgery.

It is important to avoid stimulant drugs such as cocaine, amphetamine (speed) and ecstasy as they may produce malignant hyperthermia-like problems in susceptible individuals.

Genetic counseling is recommended for anyone with a family history of myopathy, muscular dystrophy, or malignant hyperthermia.

Vicario S. Heat illness. In: Marx J, ed. Rosen’s Emergency Medicine: Concepts and Clinical Practice. 6th ed. St. Louis, Mo: Mosby; 2006:chap 139.

Review Date: 7/23/2008
Reviewed By: A.D.A.M. Editorial Team: David Zieve, MD, MHA, Greg Juhn, MTPW, David R. Eltz. Previously reviewed by Chad Haldeman-Englert, MD, Division of Human Genetics, Children's Hospitalof Philadelphia, Philadelphia, PA. Review provided by VeriMed HealthcareNetwork (7/25/2007).
The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. Copyright A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

ADAM Index