Postoperative Confusion in Schizophrenic Patients is Affected by Interleukin-6

Study Objective: 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.

Design: Prospective, randomized study.

Setting: Hakodate Watanabe Hospital and Hirosaki National Hospital.

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

Interventions: 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.

Measurements And Main Results: 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.

Conclusions: 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.