What is malignant hyperthermia?
High body temperature is known as hyperthermia. Malignant hyperthermia (MH) is a familial inherited disease in which a person experiences a rapid response to certain drugs that are used during surgeries (especially anaesthetic gases). Malignant hyperthermia is observed in the form of severe muscle contractions and a swift rise in the body temperature. The hyperthermia seen in this condition differs from that in other medical emergencies such as infection or a heat stroke.
What are its main signs and symptoms?
The common signs and symptoms of MH include:
- Body temperature that rises to 105°F (40.6°C) or even higher (Read more: Fever treatment)
- Muscle stiffness, rigidity and ache (due to an unknown cause)
- Rapid heart rate
- Acidosis
- Bleeding
- Discolouration of the urine, which could be dark brown
What are its main causes?
MH can be caused by:
- Inheritance of the condition (Even one parent carrying the disease can lead to a child developing MH).
- Other inherited muscle diseases such as:
- Multiminicore myopathy
- Central core disease
Both these diseases affect skeletal muscles, leading to muscle weakness.
How is it diagnosed and treated?
This condition is generally revealed after a person is given anaesthesia during surgery. An individual suffering from MH experiences fast and often irregular heart rate and sometimes unexplained death during anaesthesia. Hence, a family history of MH is taken by the physician before administering anaesthesia. Some of the tests that could be advised to diagnose this condition include:
- Blood tests such as:
- Clotting tests: Prothrombin time (PT) and partial thromboplastin time (PTT)
- Blood chemistry panel, which includes creatinine phosphokinase (CPK)
- Urine test to evaluate the levels of myoglobin, which is a muscle protein.
- Genetic testing
- Muscle biopsy
Management of MH includes:
- Administration of dantrolene, which is considered to be a drug of choice during an episode of MH.
- Reducing the fever or risk of further serious complications by wrapping the person in a cooling blanket.
- The person is given fluids through a vein (intravenously) during an episode of MH, which helps to prevent damage to the kidneys, thereby preserving their function.