Postoperative confusion in schizophrenic patients is affected by interleukin-6

To investigate whether epidural analgesia with local anesthetics affects postoperative confusion in schizophrenic patients or the relationships between cortisol or interleukin-6 (IL-6) and postoperative confusion.

Prospective, randomized study.

Hakodate Watanabe Hospital and Hirosaki National Hospital.

105 patients who were scheduled to undergo abdominal surgery with general anesthesia.

The schizophrenic patients were rendomly divided into two groups: patients in Group A received epidural anesthesia and patients in Group B did not receive epidural anesthesia.

Postoperative confusion during the first 48 hours after the end of operation occurred in 7 of 33 patients (21%) in Group A and 10 of 33 patients (30%) in Group B. There were no significant differences in the frequency of postoperative confusion between Groups A and B. Plasma cortisol concentrations in schizophrenic patients in Group A were significantly lower 15 minutes after incision and the end of surgery than those levels of patients in Group B; however, there was no significant difference between groups in plasma cortisol concentrations after anesthesia. Plasma IL-6 concentrations (51.7 +/- 22.0 and 31.4 +/- 8.2 pg mL(-1)) in patients with postoperative confusion at the end of surgery and 24 hours after surgery were significantly higher than those levels (34.4 +/- 16.2 and 16.9 +/- 7.7 pg mL(-1)) in patients without postoperative confusion.

Epidural anesthesia does not significantly decrease the frequency of postoperative confusion in schizophrenic patients. Plasma IL-6 concentrations at the end of the operation and 24 hours after surgery in schizophrenic patients with postoperative confusion were significantly higher than those concentrations in patients without postoperative confusion.