Can higher platelet-to-albumin ratio, red cell distribution width, and admission severity scores enhance early risk stratification for persistent acute kidney injury in intensive care unit patients? a prospective observational study

Background Acute kidney injury (AKI) is a common complication among critically ill patients and is associated with high morbidity, mortality, and progression to chronic kidney disease. Distinguishing persistent AKI (pAKI) from transient AKI (tAKI) has important prognostic implications. Red cell distribution width (RDW), platelet-to-lymphocyte ratio (PLR), platelet-to-albumin ratio (PAR), and traditional severity scores such as sequential organ failure assessment (SOFA) and acute physiology and chronic health evaluation II (APACHE II) may improve early risk stratification. Objectives To evaluate the diagnostic and prognostic performance of RDW, PLR, PAR, systemic immune-inflammation index (SII), SOFA, and APACHE II scores in differentiating pAKI from tAKI in ICU patients. Patients and methods This study included 70 patients subdivided into pAKI and tAKI according to serum creatinine level at 24, 48, and 72 h of admission, and blood samples for the RDW, PLR, PAR, systemic immune-inflammation index, were measured. To assess the severity SOFA and APACHE II scores were used. Predictive performance was assessed using receiver operating characteristic curve analysis, logistic regression, and outcome evaluation. Results pAKI patients had higher RDW, PAR, SOFA score, and creatinine across 72 h (all P <0.001). Outcomes were worse in pAKI, with lower recovery and greater need for renal replacement therapy. Receiver operating characteristic analysis showed SOFA [area under the curve (AUC) 0.739], RDW (AUC 0.692), and PAR (AUC 0.663) as significant predictors of persistence. In multivariable analysis, PAR greater than 8.14, RDW greater than 16.61%, and SOFA score greater than or equal to 5.5 were independent predictors of pAKI. Conclusion RDW, PAR, and SOFA scores are valuable tools for persistent AKI in ICU patients. Combining inflammatory markers with severity scores enhances prognostic accuracy and may aid early identification of high-risk patients.