Schizophrenic patients who develop postoperative confusion have an increased norepinephrine and cortisol response to surgery

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 microg/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 microg/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.