The association between gender, cognitive function, markers of inflammation and preoperative cerebral oxygen saturation in a cohort of preoperative cardiac surgery patients

Objective: Determination of factors influencing the preoperative cerebral oxygen saturation (rScO2) measured with near infrared spectroscopy in a cohort of cardiac surgical patients.Methods: Secondary exploratory analysis of 128 preoperative cardiac patients enrolled in a clinical trial determining the cognitive function after sevoflurane- vs propofol-based anesthesia for on-pump cardiac surgery [1] (ISRCTN44821042). Stratification of patient groups was performed by quartiles of preoperative rScO2. Quartile 1 (Q1) rScO2 < 61.0%, Q2 rScO2 = 61.0- 64.5%, Q3 rScO2 = 65.0-68.0%, Q4 rScO2 > 68.0%. Preoperative demographic data as well as cognitive tests and laboratory data were compared according to the groups.Results: Patients in the groups with lower rScO2 were older, had higher EuroScore, and showed higher levels of C-reactive protein. More female patients were in the groups with low rScO2. Patients with low rScO2 had worse results in two of four cognitive tests.Conclusion: Preoperative rScO2 is associated with several factors that have impact on postoperative outcome and might therefore serve as important non-invasive indicator for postoperative risk.