Near infrared spectroscopy for frontal lobe oxygenation during non-vascular abdominal surgery

Purpose Cerebral deoxygenation, as determined by near infrared spectroscopy (NIRS), seems to predict postoperative complications following cardiac surgery. We identify the type of non-vascular abdominal surgery associated with cerebral deoxygenation and/or hyperoxygenation, how such deviations affect patient outcome, and whether maintained cerebral oxygenation improves outcome. Methods A systematic literature search was performed on PubMed, EMBASE, Web of Science and Clinicaltrials.gov. Results A total of 901 patients from 24 publications are described. A decrease in NIRS (>15% relative to baseline) manifested with reverse Trendelenburg's positioning and in 24% (median) of especially elderly patients undergoing open surgery and demonstrated a correlation to hospital stay (LOS). However, if cerebral deoxygenation was reversed promptly, improved postoperative cognitive function (28 versus 26; mini-mental state examination) and reduced LOS (14 versus 23 days) were seen. Also, during liver transplantation (LTx), impaired cerebral autoregulation (25%), cerebral deoxygenation in the anhepatic phase (36%) and cerebral hyperoxygenation with reperfusion of the grafted liver (14%) were identified by NIRS and could lead to adverse neurological outcome, that is seizures, transient hemiparesis and stroke. Conclusion NIRS seems important for predicting neurological complications associated with LTx. Also, surgery in reverse Trendelenburg's position and in other types of abdominal surgery about one-fourth of the patients are subjected to episodes of cerebral deoxygenation that seems to predict a poor outcome. Although there are currently only few studies available for patients going through abdominal surgery, the available evidence points to that it is an advantage to maintain the NIRS-determined cerebral oxygenation.