Methods: Between December 2015 and February 2016, a total of 54 patients (42 males, 12 females; mean age 59.6±11.6 years; range, 31 to 83 years) undergoing elective cardiopulmonary bypass were prospectively included. Preparation for surgery, anesthesia, and standard data monitoring were performed in each patient with additional regional cerebral oxygen saturation monitorization. The patients underwent the Mini-Mental State Examination 24 h before and after the operation. Cerebral oximetry and blood glucose levels were sampled at pre-defined time points (T0: before anesthesia; T1: after anesthesia; T2: after ischemia; T3: after reperfusion, and T4: after surgery).

Results: No statistically significant relationship was found in the different stages of cardiopulmonary bypass between the altered cerebral oxygen saturation values and blood glucose levels. There was no significant difference between the Mini-Mental State Examination scores of the patients with respect to either presence of diabetes mellitus or timing of the test.

Conclusion: Our study findings show that glycemic changes during cardiopulmonary bypass do not alter the regional cerebral oxygenation. In addition, when other variables are kept constant, changes in the blood glucose levels do not alter postoperative neurological functions.