Peri-operative endocrine effects of etomidate.

This study investigated the effects of etomidate on endocrine responses to anaesthesia and surgery. Patients undergoing abdominal hysterectomy received standard anaesthetics of either etomidate for induction with etomidate infusion, or thiopentone and halothane. Etomidate suppressed the secretion of cortisol and aldosterone for between 8 and 22 hours after the end of the etomidate infusion; 11-deoxycortisol secretion was not suppressed during the etomidate infusion, but rose postoperatively; 17 alpha-hydroxyprogesterone suppression also lasted only as long as the etomidate infusion. There were no effects on plasma oestradiol, ACTH, or prolactin, but growth hormone concentrations were elevated in the etomidate group. Etomidate was concluded to have influenced adrenocortical function only, where it probably inhibits 11 beta-hydroxylation, 17 alpha-hydroxylation and other intramitochondrial hydroxylation reactions. There were no clinical sequelae attributable to adrenocortical suppression. The relationship of chemical structure of etomidate and other phenylated imidazoles to inhibition of steroidogenesis is discussed.