Prediction of cognitive dysfunction and patients' outcome following valvular heart surgery and the role of cerebral oximetry.

Objective: Postoperative cognitive dysfunction (POCD) commonly develops after cardiac surgery affecting patients’ outcome. Cerebral oximetrynoninvasivelymeasuresregionalcerebraloxygensaturation(rSO2)andsignificantcorrelationhasbeenreportedbetweenintraoperative cerebral desaturation and POCD, as well as patients’ outcome following coronary artery bypass grafting. However, evidence is limited in valvular heart surgery (VHS). We investigated the relationship of intraoperative rSO2 values with POCD and length of postoperative hospitalization in patients undergoing VHS.Methods:One hundredpatients undergoingelective VHS were enrolled. Neurocognitive evaluation was performed with Mini-Mental State Examination, Trail-Making Test (Part A), and Grooved Pegboard Test at 1 day before and 7th day after surgery. During surgery, rSO2wascontinuouslymonitoredand the incidenceand duration of decreaseinrSO2valuesforfiveconsecutiveminuteswere recordedas follows; (1) decrease in absolute rSO2 values to less than 50%, (2) 40%, and (3) a 20% decrease compared to baseline value. Results: Twenty-three patients (23%)demonstratedPOCD.We couldnotobserveanysignificantdifferencesineithertheincidenceorduration ofdecreaseinrSO2valuesbetween patients with and without POCD. Low education level and higher baseline temperature had significant correlation with POCD. Patients with cerebral desaturation required significantly longer postoperative hospitalization. Conclusion: In patients undergoing VHS, POCD could not be predicted with cerebral oximetry. However, patients with intraoperative cerebral desaturation required significantly longer postoperative hospitalization and cerebral oximetry appears to be promising in terms of monitoring the brain as the index organ for systemic perfusion and improving patients’ outcome. # 2008 European Association for Cardio-Thoracic Surgery. Published by Elsevier B.V. All rights reserved.