Malignant hyperthermia
Hyperthermia - malignant; Hyperpyrexia - malignant
Malignant hyperthermia is a disease that causes a fast rise in body temperature and severe muscle contractions when someone with the disease gets general anesthesia . It is passed down through families.
General anesthesia
General anesthesia is treatment with certain medicines that puts you into a deep sleep so you do not feel pain during surgery. After you receive the...
Hyperthermia means high body temperature. This condition is not the same as hyperthermia from medical emergencies such as heat stroke or infection.
Heat stroke
Heat emergencies or illnesses are caused by exposure to extreme heat and sun. Heat illnesses can be prevented by being careful in hot, humid weather...
Causes
Malignant hyperthermia is inherited. Only 1 parent has to carry the disease for a child to inherit the condition.
It may occur with some other inherited muscle diseases, such as multiminicore myopathy and central core disease.
Symptoms
Symptoms of malignant hyperthermia include:
- Bleeding
- Dark brown urine
- Muscle ache without an obvious cause, such as exercise or injury
-
Muscle rigidity
and stiffness
Muscle rigidity
Muscle cramps are when a muscle gets tight (contracts) without you trying to tighten it, and it does not relax. Cramps may involve all or part of on...
- Rise in body temperature to 105°F (40.6°C) or higher
Exams and Tests
Malignant hyperthermia is often discovered after a person is given anesthesia during surgery.
There may be a family history of malignant hyperthermia or unexplained death during anesthesia.
The person may have a fast and often irregular heart rate .
Irregular heart rate
An arrhythmia is a disorder of the heart rate (pulse) or heart rhythm. The heart can beat too fast (tachycardia), too slow (bradycardia), or irregul...
Tests for the condition may include:
- Blood clotting studies (PT, or prothombin time; PTT, or partial thrombloplastin time)
- Blood chemistry panel, including CPK (creatinine phosphokinase, which is higher in the blood when muscle is destroyed during a bout of the illness)
- Genetic testing to look for defects in the genes that are linked with the disease
-
Muscle biopsy
Muscle biopsy
A muscle biopsy is the removal of a small piece of muscle tissue for examination.
-
Urine myoglobin
(muscle protein)
Urine myoglobin
The myoglobin urine test is done to detect the presence of myoglobin in urine. Myoglobin can also be measured with a blood test.
Treatment
During an episode of malignant hyperthermia, a medicine called dantrolene is often given. Wrapping the person in a cooling blanket can help reduce fever and the risk of serious complications.
To preserve kidney function during an episode, the person may receive fluids through a vein.
Support Groups
Malignant Hyperthermia Association of the United States -- www.mhaus.org . This organization's website has a special page for patients and families that includes information and support.
Outlook (Prognosis)
Repeated or untreated episodes can cause kidney failure. Untreated episodes can be fatal.
Possible Complications
These serious complications can occur:
- Amputation
- Breakdown of muscle tissue
-
Swelling of the hands and feet and problems with blood flow and nerve function (
compartment syndrome
)
Compartment syndrome
Compartment syndrome is a serious condition that involves increased pressure in a muscle compartment. It can lead to muscle and nerve damage and pro...
- Death
- Abnormal blood clotting and bleeding
- Heart rhythm problems
- Kidney failure
-
Buildup of acid in the body fluids (
metabolic acidosis
)
Metabolic acidosis
Metabolic acidosis is a condition in which there is too much acid in the body fluids.
- Fluid buildup in the lungs
-
Weak or deformed muscles (myopathy or
muscular dystrophy
)
Muscular dystrophy
Muscular dystrophy is a group of inherited disorders that cause muscle weakness and loss of muscle tissue, which get worse over time.
When to Contact a Medical Professional
If you need surgery, tell both your surgeon and anesthesiologist before surgery if:
- You know that you or a member of your family has had problems with general anesthesia
- You know you have a family history of malignant hyperthermia
Using certain medicines can prevent the complications of malignant hyperthermia during surgery.
Prevention
Tell your health care provider if you or anyone in your family has malignant hyperthermia, especially before having surgery with general anesthesia.
Avoid stimulant drugs such as cocaine, amphetamine (speed), and ecstasy. These drugs may cause problems similar to malignant hyperthermia in people who are prone to this condition.
Genetic counseling is recommended for anyone with a family history of myopathy, muscular dystrophy, or malignant hyperthermia.
References
Curry SA, Garas M. Malignant hyperthermia. In: Ferri FF, ed. Ferri's Clinical Advisor 2015 . 1st ed. Philadelphia, PA: Elsevier Mosby; 2014:section I.
Dinarello CA, Porat R. Fever and hyperthermia. In: Fauci A, Kasper D, Longo DL, et al, eds. Harrison's Principles of Internal Medicine . 17th ed. [online version]. New York, NY: McGraw Hill; 2008:chap 17.
Platt M, Vicario S. Heat illness. In: Marx JA, Hockberger RS, Walls RM, et al, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice . 8th ed. Philadelphia, PA: Elsevier Mosby; 2013:chap 141.
Schmidt EW, Nichols CG. Heart-related illness. In: Wolfson AB, Hendey GW, Ling LJ, et al, eds. Harwood-Nuss' Clinical Practice of Emergency Medicine . 5th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2009:chap 346.
Steele MT. Rhabdomyolysis. In: Wolfson AB, Hendey GW, Ling LJ, et al, eds. Harwood-Nuss' Clinical Practice of Emergency Medicine . 5th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2009:chap 211.
Zhou J, Bose D, Allen PD, Pessah IN. Malignant hyperthermia and muscle-related disorders. In: Miller RD, ed. Miller's Anesthesia . 8th ed. Philadelphia, PA: Elsevier Saunders; 2015:chap 43.
Review Date: 4/30/2015
Reviewed By: Laura J. Martin, MD, MPH, ABIM Board Certified in Internal Medicine and Hospice and Palliative Medicine, Atlanta, GA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.