Underreporting of acute kidney injury in randomized trials of acute respiratory distress syndrome with mortality endpoints: a systematic review.

To examine how acute kidney injury is represented and reported in randomized controlled trials of acute respiratory distress syndrome with mortality as the primary endpoint. This descriptive systematic review included parallel-arm randomized controlled trials enrolling adult patients with acute respiratory distress syndrome, defined by American-European Consensus Conference or Berlin criteria, in which mortality was the primary outcome. The protocol was prospectively registered in PROSPERO (CRD420251043094). Searches were conducted in PubMed®/MEDLINE®, Embase, and Scopus for studies published between January 1st, 2005, and April 10, 2025. Two reviewers independently screened studies and extracted data by consensus. Data extraction focused on acute kidney injury reporting, use of standardized definitions, serum creatinine, renal replacement therapy, fluid balance, and kidney-related subgroup analyses. Twenty-seven randomized controlled trials met inclusion criteria. None applied standardized acute kidney injury definitions such as KDIGO, AKIN, or RIFLE. Serum creatinine was reported in two trials and renal replacement therapy in four, without details on timing or criteria. Organ dysfunction scores were commonly reported, but renal subscores were not specified. Fluid balance was reported in five trials but was not included in the adjusted analyses. No study performed mortality analyses stratified by acute kidney injury or baseline kidney function. Acute kidney injury is inconsistently represented in randomized trials of acute respiratory distress syndrome evaluating mortality. This inconsistency limits the interpretation of extrapulmonary organ dysfunction. Recognizing the multisystem nature of critical illness may improve the clinical relevance of future trial designs.