Blood urea nitrogen to serum albumin ratio independently predicts mortality and severity of community-acquired pneumonia

Abstract

BackgroundEarly studies of community-acquired pneumonia showed that nonsurvivors had higher blood urea nitrogen levels and lower serum albumin levels than survivors. Therefore, elevation of the blood urea nitrogen to serum albumin (B/A) ratio may identify patients with community-acquired pneumonia who are becoming critically ill. This study investigated the correlation between commonly used laboratory markers, in particular the B/A ratio, and clinical outcomes of community-acquired pneumonia.MethodsThis observational study was performed in consecutive patients with community-acquired pneumonia admitted to our hospital over a period of one year. Blood counts, commonly used laboratory markers, microbiological tests, and calculation of Pneumonia Severity Index (PSI) and CURB-65 were done on admission. The endpoints were mortality within 28 days of admission and requirement for intensive care.ResultsOne hundred and seventy-five patients with community-acquired pneumonia were enrolled. Nineteen patients died within 28 days of admission and 29 patients required intensive care. Using multivariate analysis, independent factors associated with mortality were the requirement for intensive care (odds ratio [OR] 14.96, 95% confidence interval [CI] 3.73–60.03, P < 0.001), PSI class (OR 3.55, 95% CI 1.08–11.66, P = 0.037), and B/A ratio (OR 1.10, 95% CI 1.01–1.20, P = 0.037). Similarly, independent factors associated with need for intensive care were PSI class (OR 5.35, 95% CI 1.90–15.06, P = 0.002), CURB-65 (OR 2.37, 95% CI 1.26–4.45, P = 0.007), and B/A ratio (OR 1.27, 95% CI 1.09–1.47, P = 0.002).ConclusionThe B/A ratio is a simple but independent predictor of mortality and severity of community-acquired pneumonia.

Predictive Values of Semi-Quantitative Procalcitonin Test and Common Biomarkers for the Clinical Outcomes of Community-Acquired Pneumonia

“…2,[10][11][12][13] We have previously shown that the combination of blood urea nitrogen and serum albumin was more accurate for predicting mortality from and severity of disease in patients with CAP than each individually. 14 Blood urea nitrogen levels are frequently elevated in patients with dehydration, whereas low serum albumin levels occur in those with malnutrition and inflammation. 38,39 Therefore, a high B/A ratio is associated with critical illness.…”

“…2,10-13 Moreover, our prior prospective observational study showed that the blood urea nitrogen/serum albumin (B/A) ratio was more accurate for predicting mortality from and severity of CAP than were blood urea nitrogen or serum albumin levels alone. 14 In this single-center retrospective study, we investigated the predictive ability of the semi-quantitative serum procalcitonin test for clinical outcomes of CAP in comparison with severity scoring systems and commonly used laboratory biomarkers.…”

Newly designed delta neutrophil index–to–serum albumin ratio prognosis of early mortality in severe sepsis

“…Although the precise mechanisms underlying the protective effects of serum albumin are not known [22], some animal studies have proposed the following mechanisms: improved arterial hyporeactivity in endotoxemia, reduced ischemia-reperfusion injury, and anti-inflammatory effects [22]. Earlier studies of patients with community-acquired pneumonia demonstrated that nonsurvivors had higher levels of blood urea nitrogen (B) and lower levels of serum albumin (A) than survivors [23]. Ugajin et al [23] reported that a higher B/A ratio on admission predicts a high mortality rate and high probability for intensive care in patients with community-acquired pneumonia.…”

“…Earlier studies of patients with community-acquired pneumonia demonstrated that nonsurvivors had higher levels of blood urea nitrogen (B) and lower levels of serum albumin (A) than survivors [23]. Ugajin et al [23] reported that a higher B/A ratio on admission predicts a high mortality rate and high probability for intensive care in patients with community-acquired pneumonia. Our study used a combination of albumin levels with DNI, which directly reflects infection.…”

Impact and indication of early systemic corticosteroids for very severe community-acquired pneumonia

“…However, most of the earlier CAP studies included patients with a mild to moderate severity of illness. In the present study, we confined our study cohort to critically ill patients, as per PSI, which is regarded as a reliable severity indicator of CAP throughout the world 20–22. This may be one of the reasons why our study showed favorable efficacy of systemic corticosteroids in reducing the risk of mortality in CAP patients.…”