Beta-endorphin and ACTH levels in the perioperative period.

1. The purpose of this study was to determine the plasma levels of beta-endorphin (beta-END) and ACTH in the perioperative period, define correlations of hormonal plasma levels with clinical parameters and establish the effect of droperidol premedication on hormonal levels and clinical parameters. 2. Twenty two were assigned to one of two groups: (1) Control (no premedication) and (2) droperidol (7.5 mg im) premedication. 3. Venous blood samples and clinical evaluations were done the day prior to surgery, just prior to induction of anesthesia and 1-1.5 hr postoperatively. 4. The results indicate that (1) expectancy of surgery on arrival to the operating room increases beta-END but not ACTH plasma levels, (2) this increase in beta-END is not affected by droperidol administration and (3) postsurgical stress increases beta-END and ACTH above operating room levels. 5. These results indicate that although beta-END and ACTH are both produced by the pituitary and derived from a common precursor, the type of stimuli (pre- versus postsurgical stress) seems to differentially affect their plasma levels.