Could not recruit any more people.

The purpose of this study is to evaluate the effects of maintaining adequate cerebral oxygen saturation (over 40%) on patients undergoing cardiac surgery. Effects on neuropsychological outcome, length of ICU stay, and length of hospital stay will be measured.

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).

Inclusion Criteria:

• Adult patient
• Elective cardiac surgery with cardiopulmonary bypass
• Coronary artery disease or valvular heart disease or combination of both
• Ability and willingness to give informed consent

Exclusion Criteria:

• Pediatric patients
• Emergency surgery
• Unable to understand English
• Allergic to tape used to attach oxygen sensor