Cortisol response to surgery and postoperative confusion in depressed patients under general anesthesia with fentanyl

The purpose of this study was to investigate the relationship between postoperative confusion and plasma cortisol response to surgery in depressed patients. We studied 80 depressed patients and 40 control patients who had undergone orthopedic surgery and perioperatively measured plasma cortisol and adrenocorticotropin levels. Postoperative confusion in the first 3 postoperative days occurred in 5 (13%) depressed patients given fentanyl during anesthesia, 13 (33%) patients without fentanyl and 1 (3%) control patients. Plasma cortisol concentration (19.7 +/- 6.9 and 19.2 +/- 8.0 microg dl(-1)) 15 min after skin incision and 60 min after the end of surgery in depressed patients with fentanyl was significantly lower than that (24.2 +/- 7.2 and 23.5 +/- 8.1 microg dl(-1)) of depressed patients without fentanyl. Plasma cortisol levels during and after surgery in depressed patients with postoperative confusion were higher than those of depressed patients without postoperative confusion. We conclude that the occurrence of postoperative confusion in depressed patients is associated with an increase in plasma cortisol levels during and after surgery. The incidence of postoperative confusion in depressed patients with fentanyl was significantly lower than that of depressed patients without fentanyl.