Background and Rationale Cerebral desaturation has previously been shown to be associated with significant morbidity in cardiac surgery postoperatively. As such, previously reported efforts have been aimed at treating intraoperative desaturation events, with early evidence suggesting that this may reduce the incidence of these adverse events. Our previous study, NIRS ICU (B2011:110) has demonstrated that significant cerebral oxygen desaturation [measured using near infrared spectroscopy (NIRS) derived cerebral oximetry] frequently occurs in the intensive care unit (ICU) within the first 24 hours following cardiac surgery. To date, no studies have addressed the early postoperative period (i.e. in the ICU) with respect to treating (and/or preventing) these desaturation events.