Citation Information :
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.
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.
Farooqui H, Jit M, Heymann DL, Zodpey S. Burden of severe pneumonia, pneumococcal pneumonia and pneumonia deaths in Indian States: Modelling based estimates. PLoS One 2015;10(6):e0129191. DOI: 10.1371/journal.pone.0129191.
Ramirez JA, Wiemken TL, Peyrani P, Arnold FW, Kelley R, Mattingly WA, et al. Adults hospitalized with pneumonia in the United States: Incidence, epidemiology, and mortality. Clin Infect Dis 2017;65(11):1806–1812. DOI: 10.1093/cid/cix647.
Eshwara VK, Mukhopadhyay C, Rello J. Community-acquired bacterial pneumonia in adults: An update. Indian J Med Res 2020;151(4):287–302. DOI: 10.4103/ijmr.IJMR_1678_19.
Grijalva CG, Nuorti JP, Griffin MR. Antibiotic prescription rates for acute respiratory tract infections in US ambulatory settings. JAMA 2009;302(7):758–766. DOI: 10.1001/jama.2009.1163.
Ahmed A, Azim A, Gurjar M, Baronia AK. Current concepts in combination antibiotic therapy for critically ill patients. Indian J Crit Care Med 2014;18:310–314. DOI: 10.4103/0972-5229.132495.
Pereira JM, Paiva JA, Rello J. Assessing severity of patients with community-acquired pneumonia. Semin Respir Crit Care Med 2012;33(3):272–283. DOI: 10.1055/s-0032-1315639.
Ugajin M, Yamaki K, Iwamura N, Yagi T, Asano T. Blood urea nitrogen to serum albumin ratio independently predicts mortality and severity of community-acquired pneumonia. Int J Gen Med 2012;5:583–589. DOI: 10.2147/IJGM.S33628.
Lim WS, van der Eerden MM, Laing R, Boersma WG, Karalus N, Town GI, et al. Defining community acquired pneumonia severity on presentation to hospital: An international derivation and validation study. Thorax 2003;58(5):377–382. DOI: 10.1136/thorax. 58.5.377.
Raz R, Dyachenko P, Levy Y, Flatau E, Reichman N. A predictive model for the management of community-acquired pneumonia. Infection 2003;31(1):3–8. DOI: 10.1007/s15010-002-2083-4.
Potgieter PD, Hammond JM. The intensive care management, mortality and prognostic indicators in severe community-acquired pneumococcal pneumonia. Intensive Care Med 1996;22(12):1301–1306. DOI: 10.1007/BF01709542.
Farr BM, Sloman AJ, Fisch MJ. Predicting death in patients hospitalized for community-acquired pneumonia. Ann Intern Med 1991;115(6):428–436. DOI: 10.7326/0003-4819-115-6-428.
Singh S, Singh K. Blood urea nitrogen/albumin ratio and mortality risk in patients with COVID-19. Indian J Crit Care Med 2022;26(5):626–631. DOI: 10.5005/jp-journals-10071-24150.
Wunderink RG, Waterer GW. Clinical practice. Community-acquired pneumonia. N Engl J Med 2014;370(6):543–551. DOI: 10.1056/NEJMcp1214869.
Malhotra RK, Indrayan A. A simple nomogram for sample size for estimating sensitivity and specificity of medical tests. Indian J Ophthalmol 2010; 58(6):519–522. DOI: 10.4103/0301-4738.71699.
Liapikou A, Ferrer M, Polverino E, Balasso V, Esperatti M, Piñer R, et al. Severe community-acquired pneumonia: Validation of the Infectious Diseases Society of America/American Thoracic Society guidelines to predict an intensive care unit admission. Clin Infect Dis 2009;48(4):377–385. DOI: 10.1086/596307.
Mandell LA, Wunderink RG, Anzueto A, Bartlett JG, Campbell GD, Dean NC, et al. Infectious Diseases Society of America/American Thoracic Society Consensus Guidelines on the management of community-acquired pneumonia in adults. Clin Infect Dis 2007;44(SUPPL. 2):S27–S72. DOI: 10.1086/511159.
Nicholson JP, Wolmarans MR, Park GR. The role of albumin in critical illness. Br J Anaesth 2000;85(4):599–610. DOI: 10.1093/bja/85.4.599.
Singanayagam A, Chalmers JD, Hill AT. Severity assessment in community-acquired pneumonia: A review. QJM 2009;102(6):379–388. DOI: 10.1093/qjmed/hcp027.
Jyothi RS, Basavaraj B, Gurupadappa K. The prognostic implication of serum albumin and BUN/Albumin ratio in assessing severity and mortality in community acquired pneumonia (CAP). Int J Clin Biochem Res 2019;6(1):79–81. DOI: 10.18231/2394-6377.2019.0020.
Shetty BV, Kulkarni SV, Nuchhi SS. Study of blood urea nitrogen to serum albumin ratio and serum albumin alone in hospitalized patients of community acquired pneumonia. J Assoc Physicians India 2020;68(1):88. PMID: 31979835.
Agarwal M, Joshi M, Gupta M, Bharti N, Chakraborti A, Sonigra M. Role of blood urea nitrogen and serum albumin ratio in predicting severity of community acquired pneumonia (CAP). Monaldi Arch Chest Dis 2021;92(3). DOI: 10.4081/monaldi.2021.2091.
Ugajin M, Yamaki K, Hirasawa N, Kobayashi T, Yagi T. Prognostic value of severity indicators of nursing-home-acquired pneumonia versus community-acquired pneumonia in elderly patients. Clin Interv Aging 2014;9:267–274. DOI: 10.2147/CIA.S58682.