Malignant Hyperthermia
Malignant Hyperthermia
Malignant hyperthermia is a severe condition that occurs in response to specific anesthetic agents. It can be triggered by genetic mutations or previous exposure to triggering anesthetics.
Show Medications for Malignant Hyperthermia
18/05/2026
Updated: 12/06/2026
Malignant Hyperthermia: A Life-Threatening Medical Condition
What is Malignant Hyperthermia?
Malignant hyperthermia (MH) is a rare but potentially life-threatening medical condition that occurs in response to certain anesthetics. It is characterized by an abnormal reaction of the body's muscles, leading to a rapid increase in body temperature and other systemic complications.Key Symptoms
The symptoms of malignant hyperthermia can be severe and may include:- Muscle rigidity and stiffness
- Tachycardia (rapid heart rate) and hypertension (high blood pressure)
- Hyperthermia (elevated body temperature), which can lead to heat stroke
- Metabolic acidosis, a condition in which the body's fluids become too acidic
- Respiratory failure, which can be life-threatening if not treated promptly
Standard Diagnostic Tests
To diagnose malignant hyperthermia, several tests may be performed. These include:- Muscle biopsy to identify ryanodine receptor mutations
- Genetic testing for RYR1 and CACNA1S gene mutations, which are associated with an increased risk of MH
- Electromyography (EMG) to assess muscle function and identify any abnormalities
Treatment of Malignant Hyperthermia
Gold Standard Treatment: Dantrolene
Dantrolene is the gold standard treatment for malignant hyperthermia. It works by inhibiting calcium ion release from the sarcoplasmic reticulum, thereby reducing muscle rigidity and stiffness. This action also helps to decrease the metabolic rate and reduce heat production in the muscles.Administration of Dantrolene
Dantrolene should be administered intravenously as soon as possible after diagnosis or suspicion of malignant hyperthermia. The recommended dose is 2-3 mg/kg, repeated every 5 minutes until symptoms resolve.Alternative Treatments
In some cases, alternative treatments may be used in conjunction with Dantrolene or when it is not available. These include:- Haloperidol: This medication works by blocking dopamine receptors in the brain, which can help to reduce muscle rigidity and stiffness.
- Midazolam: A benzodiazepine that can be used to sedate patients and reduce anxiety. It may also have a mild effect on reducing muscle tone.
- Ketamine: An anesthetic agent that can help to reduce pain and discomfort, as well as decrease muscle rigidity and stiffness.
Malignant Hyperthermia: Causes and Risk Factors
Introduction
Malignant hyperthermia (MH) is a rare but life-threatening medical emergency that can occur during general anesthesia. Understanding the causes and risk factors of MH is crucial for early detection and treatment.Risk Factors
The following are established risk factors for malignant hyperthermia:- Family History of Malignant Hyperthermia: Individuals with a family history of MH are at increased risk. This suggests a genetic predisposition to the condition.
- Previous Exposure to Triggering Anesthetics: Patients who have previously been exposed to anesthetic agents that trigger MH, such as halothane or isoflurane, may be at higher risk for developing the condition.
- Genetic Predisposition (RYR1 and CACNA1S Gene Mutations): Specific genetic mutations in the RYR1 and CACNA1S genes have been linked to an increased risk of MH. Genetic testing can identify these mutations.
- Age Under 20 Years Old: Young patients, particularly those under 20 years old, are at higher risk for developing MH during anesthesia.