Background: Regional cerebral oxygen saturation (rSO_2) is a pivotal indicator of brain ischemia during cardiovascular anesthesia. We evaluated the factors that might affect the rSO_2 values, examining the physiological parameters in two different time points during cardiopulmonary bypass (CPB). Methods: Fifty-nine patients undergoing cardiovascular surgery with CPB were retrospectively enrolled and their rSO_2 values were measured 30 min after aortic clamping (T1) and 30 min after the T1 measurement (T2). At each time point, the PaCO_2 was measured by arterial blood samples. Percent changes in the rSO_2 values were compared with percent changes in all parameters at each time point. Results: Percent changes in the rSO_2 values significantly correlated with percent changes in the PaCO_2 values on the left and right sides of the forehead (r = 0.417 vs. r = 0.387
arterial blood gas analysis
carbon dioxide
cardiopulmonary bypass
cardiovascular anesthesia
regional cerebral oxygen saturation