Role of Blood Urea Nitrogen to Serum Albumin Ratio (BAR) in the Prediction of Acute Kidney Injury in Intensive Care Units

Background: The incidence of acute kidney injury (AKI) is higher than previously thought, with over 50% of ICU cases developing stage 1 AKI, while stages 2 and 3 are less frequent, and about 10% require RRT. Aim: To assess the role of the BUN to serum albumin ratio in the prediction of AKI in cases admitted to the ICU. Patients and methods: 100 ICU patients (47 high BAR, 53 low BAR) from two hospitals were included. Adults (≥18 years) were included, excluding those with ESRD, repeat ICU admissions, or short stays. Baseline data, kidney function, and AKI incidence (KDIGO criteria) were assessed at admission and 48 hours. Results: Insignificant variance in creatinine levels among groups at admission, but patients with a low blood urea nitrogen to serum albumin ratio (BAR) had significantly lower BUN and BAR, along with higher albumin levels compared to those with a high BAR. At 48 hours of admission, patients with a high BAR showed significantly higher (BUN), creatinine, and BAR, but lower albumin concentrations than those with a low BAR. Additionally, cases with a high BAR had a significantly greater incidence of AKI. BAR additionally demonstrated a significant positive correlation with age, BUN, and sodium, but a significant negative correlation with albumin and hemoglobin (HB). At a cutoff value of 5.2, BAR demonstrated 93% sensitivity and 80% specificity for predicting acute kidney injury. Conclusion: High BAR individuals have a higher risk of AKI, with positive correlations between age, BUN, Na, and BAR, and a 93% sensitivity and 80% specificity.