NMDA receptor antagonists are reported to be effective for improving depression. It remains unclear whether ketamine, which is an NMDA receptor antagonist, postoperatively affects the psychological state in depressed patients. We investigated the effect of 1.0 mg/kg of ketamine on postoperative outcomes in depressed patients.

We investigated the relationship between postoperative confusion and duration of benzodiazepine exposure, preoperative anxiety, depressive state, and cognitive function in elderly patients regularly taking benzodiazepines. We studied 328 patients ranging in age from 65 to 80 yr who underwent orthopedic surgery. Information on benzodiazepine use was obtained by face-to-face interview and visual assessment of the patient's medicine chest. Postoperative confusion was assessed by using a confusion-assessment method. The patients were divided into two groups: those who regularly took benzodiazepines and those who did not. Fifty-seven (17%) of 328 patients were treated with benzodiazepines. There were no significant differences in preoperative Mini-Mental State (MMS) scores, anxiety scores, or depression scores between benzodiazepine users and nonusers. Postoperative confusion occurred in 15 (26%) of 57 benzodiazepine users and in 34 (13%) of 271 nonusers (P < 0.01). The patients who had a score <23 on the MMS were 5 (9%) of 57 benzodiazepine users and 8 (3%) of 271 nonusers (P < 0.05). Postoperative confusion occurred in 13 (35%) of 37 long-term benzodiazepine users (daily use for >1 yr) and in 2 (10%) of 20 short-term users (daily use for <1 yr). The incidence of postoperative confusion was significantly more frequent in long-term than in short-term benzodiazepine users or nonusers of benzodiazepines. The patients who developed a score <23 on the MMS were 5 (14%) of 37 long-term benzodiazepine users and 0 (0%) of 20 short-term benzodiazepine users. In conclusion, the incidence of postoperative confusion was significantly more frequent in long-term benzodiazepine users.

No abstract

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 µg 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 µg 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.

The purpose of this study was to investigate the relationship between postoperative confusion and the plasma norepinephrine (NE), adrenocorticotropin (ACTH) or cortisol response to surgery in schizophrenic patients. We studied 50 schizophrenic patients and 35 control patients who underwent orthopedic surgery and perioperatively measured plasma NE, ACTH and cortisol levels. Postoperative confusion during 72 h after the end of the operation occurred in 14 of 50 schizophrenic patients (28%) and in 2 of 35 control patients (6%). Plasma NE levels 15 min after skin incision, the next day, the second day and the third day after operation in schizophrenic patients with postoperative confusion (668.0 ± 59.2, 522.0 ± 96.5, 463.2 ± 71.2 and 398.9 ± 56.2 pg/ml, respectively) were significantly higher than those in schizophrenic patients without confusion (524.1 ± 62.6, 342.4 ± 38.6, 311.2 ± 58.3 and 314.1 ± 77.1 pg/ml, respectively). Plasma cortisol levels 15 min after the skin incision and the next and second days after operation in schizophrenic patients with postoperative confusion (23.6 ± 3.2, 21.1 ± 4.3 and 19.9 ± 4.4 µg/dl, respectively) were significantly higher than those in schizophrenic patients without confusion (15.2 ± 4.5, 14.3 ± 5.1 and 13.8 ± 3.8 µg/ dl, respectively). In conclusion, the occurrence of postoperative confusion in schizophrenic patients is associated with an increase in plasma norepinephrine and cortisol levels during and after surgery.