Changes in Cerebral Oxygenation During the Administration of Cell Saver Blood and Allogeneic Blood

This prospective study will include patients presenting for spinal surgery. There will be no change in the anesthetic or perioperative care of these patients. Per our usual clinical routine, cell saver will be used intraoperatively to limit the need for allogeneic blood. Tissue and cerebral oxygenation will be monitored using near infrared spectroscopy (NIRS). The device is applied non-invasively like pulse oximetry to a muscle bed (usually the deltoid) and the forehead to measure tissue oxygenation. These devices are used routinely in the operating room and the cardiothoracic intensive care unit. Although not used on every major orthopedic procedure, these devices are routinely used in various high risk clinical scenarios. As clinically indicated, cell saver blood (autologous) or allogeneic blood will be administered. During this time, tissue and cerebral oxygenation will be recorded every 5 minutes starting 10 minutes before the transfusion and continued for 30 minutes following the transfusion.