At present, the most specific and sensitive test for the diagnosis of malignant hyperthermia (MH) susceptibility is the Halothane caffeine contracture test. In this test, a small piece of muscle is obtained under regional or general anaesthesia and while still viable is placed in a special solution and attached to a device which measures the force of contraction. The muscle strip is then exposed to either Halothane or caffeine and the response measured. A response to Halothane or a response to low concentrations of caffeine are considered diagnostic for MH susceptible muscle. The main centre for investigation of MH in the UK is based in Leeds. All biopsies must be performed at the diagnostic centre, since the muscle must be fresh when tested.
[i] Malignant hyperthermia: advances in clinical management and diagnosis.
Br J Anaesth 2000; 85(1): 118-28.
Related examination questions
1. Describe the Halothane contracture test. How is it performed?