What is in vitro contracture test?

What is in vitro contracture test?

The in vitro contracture test determines the sensitivity of freshly obtained skeletal muscle specimens to caffeine or halothane applied to a bathing solution. Muscles from persons susceptible to malignant hyperthermia have lower contracture thresholds for these agents than do normal muscle.

How do you test for malignant hypothermia?

The abnormal gene that makes you susceptible to malignant hyperthermia is identified using genetic testing. A sample of your blood is collected and sent to a lab for analysis. Genetic testing can reveal changes (mutations) in your genes that may make you susceptible to malignant hyperthermia.

What is the best laboratory test available for diagnosing patients with MH?

The caffeine halothane contracture test (CHCT) is the criterion standard for establishing the diagnosis of malignant hyperthermia (MH). The test is performed on freshly biopsied muscle tissue at 30 centers worldwide; one of these centers is located in Canada, and four are located in the United States.

What are the early signs of malignant hyperthermia?


  • Severe muscle rigidity or spasms.
  • Rapid, shallow breathing and problems with low oxygen and high carbon dioxide.
  • Rapid heart rate.
  • Abnormal heart rhythm.
  • Dangerously high body temperature.
  • Excessive sweating.
  • Patchy, irregular skin color (mottled skin)

What does dantrolene treat?

Dantrolene is used to treat spasticity (muscle stiffness and tightness) or muscle spasms associated with spinal cord injuries, stroke, multiple sclerosis, or cerebral palsy.

What is IVCT test?

Currently, the in vitro contracture test (IVCT) requiring an open muscle biopsy is the only reliable procedure to diagnose MH susceptibility in affected patients.

What is the antidote for malignant hyperthermia?

Dantrolene is the only currently accepted specific treatment for MH. In an episode of MH, muscle metabolism is dramatically increased secondary to an increase in calcium within the muscle. This causes muscles to contract, ATP hydrolysis, and heat production.

Which disease is most associated with malignant hyperthermia?

The most common of these conditions are Duchenne and Becker muscular dystrophy. Although rhabdomyolysis with hyperkalemia can be a feature of MH, the MH syndrome usually manifests signs of hypermetabolism, such as respiratory acidosis, metabolic acidosis, and excessive heat production.

What does a positive caffeine halothane contracture test indicate?

The caffeine-halothane contracture test (CHCT) is the only recognized laboratory test to diagnose malignant hyperthermia (MH). The authors report the results of their analysis of pooled data from the North American Malignant Hyperthermia Registry database to determine the sensitivity and specificity of the CHCT.

What can be mistaken for malignant hyperthermia?

In addition to the conditions listed in the differential diagnosis, there are a number of other conditions and circumstances that may mimic malignant hyperthermia (MH), including the following: Contrast dye. Diabetic coma. Drug toxicity.

Which skeletal muscle relaxant can trigger MH?

All inhalation anesthetics except nitrous oxide are triggers for MH. The muscle relaxant succinylcholine is also a trigger for MH.

Who should not use dantrolene?

Dantrolene should not be given to a child younger than 5 years old.