A New Predictor of Mortality in COVID-19 Pneumonia: The BUN/Lymphocyte Ratio

Abstract

Objective: The high mortality and transmission rates of Coronavirus disease-2019 (COVID-19) lead to severe difficulties being experienced in emergency department management. This study investigated whether the blood urea nitrogen/lymphocyte ratio (BLR) and neutrophil/albumin ratio (NAR) can predict mortality in COVID-19 patients in the emergency department. Methods: Four hundred sixty-one COVID-19 patients presenting to the emergency department between March 2020 and January 2022 were included in the study. Patients' demographic characteristics and laboratory parameters and outcomes were recorded. The power of the data in predicting mortality was calculated and compared with the Pneumonia Severity Index (PSI) and CURB-65. Results: Women constituted 277 (60.1%) patients in the study, and men 184 (39.9%). The patients' median age was 69 (interquartile range: 20). In-hospital mortality was determined at 30.5%. ROC analysis was performed to determine the ability of the PSI, CURB-65, the NAR, and BLR to predict mortality in patients with COVID-19. The BLR was found to exhibit a better performance than PSI, CURB-65, and NAR values, and to be capable of use in differentiating mortality with 64.5% sensitivity and 62.8% specificity (p<0.05). The BLR also exhibited a high negative predictive value (80.08%) in the diagnosis of sepsis. A negative BLR value emerged as a powerful independent variable in excluding sepsis and predicting low mortality rates. Conclusion: The BLR was the most accurate predictor of COVID-19 pneumonia-related critical care requirements in this study. It is also a reliable predictor with a powerful negative predictive value for the planned discharges from the emergency department.

Keywords

• covid-19
• pneumonia
• mortality
• predictor