The Effects of Monitoring and Maintaining Cerebral Oxygen Saturation on Neuropsychological Outcomes in Patients Undergoing Cardiac Surgery

Central nervous system dysfunction is a major cause of morbidity after cardiac surgery. This study seeks to evaluate the effects of cerebral oxygen saturation on the neuropsychological outcome of cardiac surgery patients. Currently, monitoring of cerebral oxygen saturation levels is not part of routine and standard practice.

Subjects will be assigned to a control and intervention group. Anesthesia and surgery will be performed as per usual standards of care. Patients in both groups will be monitored with an oxygen sensor placed over the forehead. The data will be recorded continuously on a floppy disk. The control group will be treated according to current standard of care; the readings of brain oxygen saturation will not be visible to the clinician. In the intervention group, the reading of brain oxygen saturation will be monitored by the anesthesiologist throughout surgery. Interventions will be performed to maintain cerebral oxygen saturations above 40%. Neuropsychological tests will be completed pre-operatively and at two time points post-operatively. The tests used are the ASEM (antisaccadic eye movement) and the MMSE (mini-mental state examination).