Integrated analysis of Platelet-to-Albumin ratio and other laboratory markers for early detection of acute kidney injury in ICU patients

Background Acute kidney injury (AKI) is a common and serious condition among hospitalized and critically ill patients and is associated with increased morbidity and mortality compared with patients without AKI. The aim of this study is to evaluate prognostic values of inflammatory indices and clinical severity scores in ICU patients with AKI, comparing demographic, clinical, and laboratory characteristics between AKI and non-AKI patients. Patients and methods This prospective observational cohort study was conducted at Assiut University Hospital ICU (September 2024–2025). A total of 140 critically ill patients were included and classified into AKI ( n =70) and non-AKI ( n =70). Platelet-to-albumin ratio (PAR), red cell distribution width (RDW), platelet-to-lymphocyte ratio, systemic immune-inflammatory index (SII), and severity scores were assessed. Ethical approval and informed consent were obtained. Results Patients with AKI had significantly longer ICU stays and worse renal function (higher BUN, creatinine, and albumin/creatinine ratio). They also showed higher potassium, phosphate, lower albumin, elevated CRP, and more pyuria and albuminuria. Hematologically, AKI patients had higher platelet counts and lower lymphocytes. Inflammatory indices (PAR, platelet-to-lymphocyte, RDW) and severity scores [sequential organ failure assessment (SOFA), APACHE II, SII] were all significantly higher. APACHE II had the highest diagnostic accuracy for predicting AKI, followed by SOFA and PAR, while RDW had the lowest, indicating that AKI is associated with worse clinical, laboratory, and inflammatory profiles compared with non-AKI cases. Conclusion PAR, RDW, and SOFA are valuable predictors of AKI in ICU patients, reflecting inflammation, nutritional imbalance, and disease severity.