Cerebral oximetry and preventing neurological complication post-cardiac surgery: a systematic review

This systematic review aims to provide an up-to-date summary of the current literature examining the relationship between intraoperative regional cerebral oxygen saturation and neurological complications after cardiac surgery.

Observational and interventional studies investigating the link between regional cerebral oxygen saturation and postoperative delirium, cognitive dysfunction and stroke were included. After database searching and study screening, study characteristics and major findings were extracted.

Twenty-seven studies were identified. Of the observational studies (n = 17), 8 reported that regional cerebral oxygen desaturations were significantly associated with neurological complications after cardiac surgery. Of the interventional studies (n = 10), 3 provided evidence for monitoring cerebral oximetry during cardiac surgery as a means of reducing incidence of postoperative cognitive dysfunction or stroke. There was significant heterogeneity in the tools and rigor used to diagnose neurological complications.

Studies to date show an inconsistent relationship between regional cerebral oxygen saturation and neurological outcomes after cardiac surgery, and lack of clear benefit of targeting cerebral oximetry to minimize neurological complications. Standardized assessments, definitions of impairment and desaturation thresholds will help determine the benefits of cerebral oximetry monitoring during cardiac surgery.