Urinary Biomarkers of Acute Kidney Injury in Critically Ill Patients at an Intensive Care Unit in Cross River State

Acute kidney injury in critically ill patients is associated with high mortality in Nigerian intensive care settings, and early detection using novel urinary biomarkers may improve management outcomes. This study evaluates urinary biomarkers of acute kidney injury, specifically neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), and cystatin C, in critically ill patients at an intensive care unit in Cross River State, South South Nigeria. A prospective observational design was adopted, recruiting 80 critically ill adults admitted to the ICU over a six-month period. Urinary NGAL, KIM-1, and cystatin C were measured at ICU admission and at 24, 48, and 72 hours. Conventional renal markers including serum creatinine and urine output were monitored in parallel. Acute kidney injury was classified according to KDIGO criteria. Receiver operating characteristic analysis compared the early diagnostic performance of urinary biomarkers against serum creatinine. The relationship between biomarker kinetics and ICU mortality was also assessed. Findings will contribute to the development of early AKI detection protocols using novel urinary biomarkers in resource-limited Nigerian ICU settings. Keywords: acute kidney injury, NGAL, KIM-1, intensive care, Cross River State.