Preoperative regional cerebral oxygen saturation is a predictor of postoperative delirium in on-pump cardiac surgery patients: a prospective observational trial.

Schoen, Julika; Meyerrose, Joscha; Paarmann, Hauke; Heringlake, Matthias; Hueppe, Michael; Berger, Klaus-Ulrich

INTRODUCTION Postoperative delirium is an important problem in patients undergoing major surgery. Cerebral oximetry is a non-invasive method to detect imbalances in the cerebral oxygen supply/demand-ratio. Low preoperative cerebral oxygen saturation (ScOâ‚‚) levels have been associated with postoperative delirium in non-cardiac surgery patients. The present prospective observational study determines the relationship between pre- and intra-operative ScOâ‚‚ levels and postoperative delirium in patients undergoing on-pump cardiac surgery. METHODS After approval of the local ethical committee and written informed consent, N = 231 patients scheduled for elective/urgent cardiac surgery were enrolled. Delirium was assessed by the confusion-assessment-method for the intensive care unit (CAM-ICU) on the first three days after surgery. ScOâ‚‚ was obtained on the day before surgery, immediately before surgery and throughout the surgical procedure. Preoperative cognitive function, demographic, surgery related, and intra- and post-operative physiological data were registered. RESULTS Patients with delirium had lower pre- and intra-operative ScOâ‚‚ readings, were older, had lower mini-mental-status-examination(MMSE) scores, higher additive EuroScore and lower preoperative haemoglobin-levels. The binary logistic regression identified older age, lower MMSE, neurological or psychiatric disease and lower preoperative ScOâ‚‚ as independent predictors of postoperative delirium. CONCLUSIONS The presented study shows that a low preoperative ScOâ‚‚ is associated with postoperative delirium after on-pump cardiac surgery.