Review ArticlesContinuous Near-infrared Spectroscopy Monitoring in Adult Traumatic Brain Injury: A Systematic ReviewMathieu, François MD*,†; Khellaf, Abdelhakim DCS‡,§; Ku, Jerry C. MD*; Donnelly, Joseph MBChB, PhD∥; Thelin, Eric P. MD, PhD¶; Zeiler, Frederick A. MD, PhD, FRCSC†,#,**,††Author Information *Division of Neurosurgery, University of Toronto, Toronto, ON ‡Faculty of Medicine, McGill University, Montreal, QC Departments of #Surgery ††Human Anatomy and Cell Sciences, Rady Faculty of Health Sciences, University of Manitoba **Biomedical Engineering, Faculty of Engineering, University of Manitoba, Winnipeg, MB, Canada †Division of Anaesthesia, Addenbrooke’s Hospital, University of Cambridge §Department of Clinical Neurosciences, Division of Neurosurgery, University of Cambridge, Cambridge, UK ∥Department of Anaesthesiology, University of Auckland, Auckland, New Zealand ¶Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden F.M. has received salary support for dedicated research time from the Canada Cambridge Scholarship funded by the Cambridge Commonwealth Trust. F.A.Z. has received salary support for dedicated research time. Such salary support came from: the Cambridge Commonwealth Trust Scholarship and the University of Manitoba Clinician Investigator Program. F.A.Z.’s research program is supported through the University of Manitoba Thorlakson Chair in Surgical Research Establishment Fund. E.P.T. has received post-doctoral scholarships from the Swedish Society for Medical Research (Svenska Sällskapet för Medicinsk Forskning). The remaining authors have no funding or conflicts of interest to disclose. Address correspondence to: François Mathieu, MD. E-mail: firstname.lastname@example.org. Journal of Neurosurgical Anesthesiology: October 2020 - Volume 32 - Issue 4 - p 288-299 doi: 10.1097/ANA.0000000000000620 Buy SDC Metrics Abstract Near-infrared spectroscopy (NIRS) may provide a noninvasive way to monitor cerebral oxygenation in patients with traumatic brain injury, therein allowing for timely intervention aimed at reversing regional brain tissue hypoxia. We conducted a systematic review of NIRS-based oximetry measurements and their association with (A) patient functional outcome (B) other neurophysiological parameters. We searched MEDLINE, EMBASE, SCOPUS, BIOSIS, GlobalHealth and Cochrane Databases from inception to December 2018 and relevant conference proceedings published over the last 5 years. A total of 42 studies meeting our inclusion criteria were found (37 prospective observational, 5 retrospective designs). Seven studies reporting on the association between NIRS-based cerebral oxygenated hemoglobin measurements, mortality, modified Rankin Scale, Glasgow Outcome Scale, or Extended Glasgow Outcome Scale were identified. Forty-two studies exploring associations with neurophysiological parameters were included. Notwithstanding significant gaps in the currently available literature, our analysis suggests a link between NIRS-detected cerebral hypoxia during the acute phase of traumatic brain injury and poor functional outcome. NIRS measurements appear to reflect changes in intracranial pressure, invasively monitored brain tissue oxygen tension and various cerebrovascular reactivity indices although low quality contradicting data exist. More importantly, our review highlights the need for more prospective work before routine integration of NIRS-based techniques into multimodality monitoring regimen. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.