Neurologic and cognitive decline remain common complications that adversely affect patients' outcome after cardiac surgery. By incorporating a brain monitor that measures cerebral oxygen content into our perioperative management we aim to decrease postoperative neurologic and cognitive deficits and improve quality of life in this patient population. We also aim to uncover how the compromised brain alters its metabolism in response to ischemic injury and how this new information can guide new preventive treatment methods for vulnerable patients.