Acute kidney injury and COVID-19: the predictive power of BUN/albumin ratio for renal replacement therapy requirement.

Objective: To investigate the predictive power of the BUN/albumin ratio (BAR) measured in the emergency department (ED) for the requirement of renal replacement therapy (RRT) in patients admitted to the intensive care unit (ICU) with severe COVID-19 pneumonia and acute kidney injury (AKI).

Materials And Methods: The study included 117 patients with AKI who were admitted to the ICU and had COVID-19 pneumonia detected on chest computed tomography (CT) taken in the ED's pandemic area between November 1, 2020, and June 1, 2021. The predictive power of laboratory values measured at the time of ED admission for the requirement of RRT was analyzed.

Results: Of the patients, 59.8% (n = 70) were male, with an average age of 71.7 ± 14.8 years. The mortality rate of the study was 35% (n = 41). During follow-up, 23.9% (n = 28) of the patients required RRT. Laboratory parameters measured at the time of ED admission showed that patients who required RRT had significantly higher BAR, BUN, and creatinine levels, and significantly lower albumin levels (all p < 0.001). ROC analysis to determine the predictive characteristics for RRT requirement revealed that the BAR had the highest AUC value (AUC, 0.885; 95% CI 0.825-0.945; p < 0.001). According to the study data, for BAR, a cut-off value of 1.7 resulted in a sensitivity of 96.4% and a specificity of 71.9%.

Conclusion: In patients with severe pneumonia who develop acute kidney injury, the BUN/albumin ratio may guide clinicians early in predicting the need for renal replacement therapy.