Serial Urinary Albumin-to-Creatinine Ratio as an Early Predictor of 28-Day Mortality and Organ Dysfunction in Critically Ill Patients with Sepsis: A Prospective Observational Study

Background: Sepsis is a life-threatening organ dysfunction that remains a leading cause of intensive-care-unit (ICU) mortality. Endothelial injury and capillary leak in sepsis increase glomerular albumin excretion, making urinary albumin-to-creatinine ratio (ACR) a candidate bedside prognostic marker. Aims/Objectives: To determine whether urinary ACR measured within 24 hours of ICU admission predicts 28-day all-cause mortality, and to assess its association with organ-dysfunction severity (SOFA, APACHE IV). Methodology: This prospective observational study enrolled 250 adult ICU patients (170 septic, 80 non-septic) at a tertiary-care centre over one year. Spot urine ACR was measured at admission and at 24 hours (ΔACR = ACR24 − ACR-admission). SOFA and APACHE IV were recorded, and patients were followed for 28 days for mortality and organ support. Results: Septic patients had significantly higher admission ACR than non-septic patients (344.92 ± 138.51 vs 81.63 ± 41.94 mg/g; p<0.001) and 28-day mortality (45.9% vs 11.2%; p<0.001). Among septic patients, admission ACR did not differ between survivors and non-survivors, but 24-hour ACR (580.39 ± 165.04 vs 390.76 ± 151.37 mg/g; p<0.001) and rising ΔACR were strongly associated with death; all patients with ΔACR >150 mg/g died. ACR correlated positively with SOFA (r=0.481–0.685) and APACHE IV (r=0.504–0.673; p<0.001). On multivariate analysis, ΔACR remained an independent predictor of mortality (OR 1.017; p=0.008). Conclusions: Serial urinary ACR is a simple, rapid, inexpensive, non-invasive biomarker for early prediction of mortality and organ dysfunction in sepsis; a rising ΔACR over the first 24 hours independently signals poor prognosis and may aid early risk stratification.