Validity of Blood Urea Nitrogen to Serum Albumin Ratio as an Independent Biomarker to Predict Severity and Mortality of Community-acquired Pneumonia

Background and objective: Certain serum biomarkers have been reported to predict the severity and mortality of community-acquired pneumonia (CAP). There is a dearth of studies on this subject in the Indian population in patients with CAP. The present prospective observational study was conducted to find the utility of the blood urea nitrogen (BUN)/serum albumin (B/A) ratio as a biomarker to predict the severity and mortality in patients with CAP. Materials and methods: All 90 patients aged ≥ 18 years of either sex, with a new radiographic infiltrate, were included. Various biochemical parameters such as BUN, serum albumin, and procalcitonin were tested. The serum B/A ratio was calculated. A chest radiograph was obtained. Patients were followed up for the duration of their stay in hospital till discharge or death. Results: The sensitivity and specificity of the B/A ratio at the optimum cut-off value of 10.66 to predict the severity of CAP was about 79.0%, whereas the sensitivity and specificity of the procalcitonin at the optimum cut-off value of 1.50 ng/dL to predict the severity of CAP were 71.15 and 84.21%, respectively. The sensitivity and specificity of the B/A ratio at the optimum cut-off value of 19.8 to predict the mortality of CAP was about 99.0%, whereas the sensitivity and specificity of the procalcitonin at the optimum cut-off value of 5.55 ng/dL to predict the mortality of CAP was about 92.0%. Conclusion: The B/A ratio and procalcitonin are simple but independent predictors of mortality and severity of CAP. How to cite this article: Ginwala A, Pujari S, Phalgune D, Kulkarni V, Bahulikar A. Validity of Blood Urea Nitrogen to Serum Albumin Ratio as an Independent Biomarker to Predict Severity and Mortality of Community-acquired Pneumonia. Indian J Crit Care Med 2025;29(4):333-337.