A method for identifying mechanisms of neurologic injury from cardiac surgery.

Background: A method for linking discrete surgical and perfusion-related processes of care with cerebral emboli, cerebral oxyhemoglobin desaturation, and hemodynamic changes may offer opportunities for reducing overall neurologic injury for patients undergoing cardiac surgery.

Methods: An intensive intraoperative neurologic and physiologic monitoring approach was developed and implemented. Mechanisms likely to produce embolic (cerebral emboli), hypoperfusion (oxyhemoglobin desaturation), and hypotensive (hemodynamic changes) neurologic injuries were monitored and synchronized with the occurrence of surgical and perfusion clinical events/techniques using a case video.

Results: The system was tested among 32 cardiac surgery patients. Emboli were measured in the cerebral arteries and outflow of the cardiopulmonary bypass circuit among nearly 75% and 85% of patients, respectively. Oxyhemoglobin desaturation was measured among nearly 70% of patients. Hemodynamic information was recorded in 100% of patients.

Conclusions: We developed and successfully implemented a method for detailed real-time associations between processes of clinical care and precursors of neurologic injury. Knowledge of this linkage will result in the redesign of clinical care to reduce a patient's risk of neurologic injury.