An example of the intraoperative urinary oxygen partial pressure, mean arterial pressure (MAP), oxygen saturation measured by pulse oximetry (Spo₂), and cerebral oximetry tracings from a patient who subsequently developed acute kidney injury. The black lines indicate the start and end of cardiopulmonary bypass (CPB). The gray box highlights a time period of both hypotension and hypoxemia after bypass. During this period, there was also a decrease in both cerebral oximetry and urine oxygen. MAP, red; Spo₂, green; right cerebral oximetry, blue; left cerebral oximetry, purple; urine oxygen partial pressure, yellow. CABG, coronary artery bypass graft.