The objective of this systematic review was to clarify the status of near-infrared spectroscopy (NIRS) in monitoring perioperative renal regional tissue oxygen saturation (rSO₂) and determine whether there is evidence supporting its use in predicting postoperative acute kidney injury (AKI).

A systematic search of electronic databases was conducted to identify all clinical studies that utilized NIRS to monitor renal rSO₂ during the perioperative period to observe postoperative AKI.

Studies published online as of May 31, 2024, were included in the review.

Studies involving human participants undergoing surgery with a predefined outcome of AKI were included.

Regional tissue oxygen saturation was measured using NIRS.

A total of 144 records were identified in the primary search after removing duplicates. After screening, 18 studies were included in the analysis, consisting of 3 case-control studies and 15 prospective cohort studies. Thirteen reports focused on pediatric surgery, whereas five reports focused on adult surgery. Sixteen studies involved cardiovascular surgery with cardiopulmonary bypass, and two studies focused on liver surgery. All studies received a quality score of 7 or above. Significant heterogeneity and mostly short follow up periods were noted.

Renal desaturation may indicate AKI in patients; however, further studies are required to substantiate this relationship. Additional clinical trials are necessary to evaluate normal values and establish the exact threshold of renal rSO₂ that signifies a meaningful decline in renal function.