Diagnostic Accuracy of Albumin Levels in Predicting Colistin-Induced Nephrotoxicity in Critically ill Patients in the Intensive Care Unit

Introduction: Colistin is an antibiotic utilized for the treatment of drug-resistant bacterial infections. Despite its efficacy, colistin is associated with significant nephrotoxicity, reported in up to 40% of cases. Hypoalbuminemia has been identified as a potential risk factor for acute kidney injury (AKI), but its predictive role in colistin-induced nephrotoxicity remains unclear. This study examines the relationship between hypoalbuminemia and the occurrence of AKI in critically ill patients undergoing colistin treatment. Methods: This retrospective cohort study was conducted in a tertiary intensive care unit between 2020 and 2022. Patients aged 18 years or older who received colistin for at least 48 hours were included, excluding those with chronic kidney disease, high-dose vasopressor use, or advanced liver failure. Data on demographics, clinical characteristics, and laboratory findings were collected. AKI was diagnosed using KDIGO criteria, and hypoalbuminemia was defined as albumin <2.5 g/dL. Statistical analyses, including logistic regression, were performed using SPSS 26.0, with significance set at p<0.05. Results: Among 104 patients, 49 (47.1%) developed AKI. Patients with AKI were older (mean age 66.7 vs. 59.1 years, p=0.016) and had longer durations of hypoalbuminemia (median 18 vs. 6 days, p<0.001). Hypoalbuminemia at the start of colistin therapy was significantly associated with AKI (p<0.001). Logistic regression identified low albumin levels as an independent predictor of AKI (odds ratio 0.14, p=0.005). Mortality was higher in the AKI group (57% vs. 43%, p=0.003). Conclusion: Hypoalbuminemia is a significant predictor of colistin-induced AKI. Early identification and management of hypoalbuminemia may reduce nephrotoxicity and improve outcomes in critically ill patients receiving colistin therapy. Further multicenter studies are recommended to validate these findings.