Etomidate anesthesia inhibits the cortisol response to surgical stress.

Plasma cortisol was measured in 18 patients undergoing gynecological procedures under etomidate or methohexital and nitrous oxide anesthesia. Plasma ACTH was also measured in three patients in each group. The mean plasma cortisol concentration before anesthesia was comparable in both groups. Plasma cortisol increased in patients anesthetized with methohexital, while none of the patients anesthetized with etomidate had an increase in plasma cortisol. The increase in plasma ACTH was equivalent in the two groups. Therefore, etomidate is a potent inhibitor of the adrenal response to surgery. The absence of clinical consequences associated with the blunted response suggests that a major increase in adrenal hormone production may not be necessary during surgery.