Adrenal cortical reserve in patients undergoing muscle biopsy for malignant hyperthermia screening.

Stress has been suggested as a factor involved in the development of a malignant hyperthermia (MH) reaction. This study has compared the hormonal response of a group of patients susceptible to MH (MHS), with that of a control group, during diagnostic muscle biopsy under general anaesthesia. Preoperative adrenal cortical reserve was assessed using the Short Synacthen Test (SST). There was no significant difference between the groups in their hormonal response to the procedure, both groups showing a peroperative reduction in plasma cortisol concentration from an initially high value, and the SST was within accepted normal limits for both groups. It was concluded that patients susceptible to MH have normal adrenal cortical reserve and responded normally to the psychological and surgical stress encountered during this study.