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Kidney Week

Abstract: TH-PO1145

Persistent Increase in the Blood Urea Nitrogen/Creatinine Index (PI-BUN/Cr) Phenotypes the Clinical Course of Patients with Severe COVID-19

Session Information

  • COVID-19
    October 24, 2024 | Location: Exhibit Hall, Convention Center
    Abstract Time: 10:00 AM - 12:00 PM

Category: Coronavirus (COVID-19)

  • 000 Coronavirus (COVID-19)

Authors

  • Casas-Aparicio, Gustavo Alejandro, Instituto Nacional de Enfermedades Respiratorias, Mexico, DF, Mexico
  • Claure-Del Granado, Rolando, Hospital Obrero No 2, Division de Nefrologia, Cochabamba, Bolivia, Plurinational State of
Background

PI-BUN/Cr in patients with COVID-19 is an important clinical marker that extends beyond simple prerenal injury, reflecting more complex underlying pathophysiological processes. Understanding and interpreting PI-BUN/Cr in this context is crucial due to its potential implications for mortality.

Methods

We analyzed a retrospective and longitudinal cohort of patients admitted to a single center in Mexico City. Between March 5, 2020, and August 25, 2021, patients with confirmed positive diagnosis for SARS-CoV-2, age >18 years, and a ratio of partial oxygen pressure to inspired oxygen fraction <300 mmHg on admission were included. Data was obtained from electronic medical records. PI-BUN/Cr was defined as an increase in the BUN/Cr ratio >30 in more than 60% of the measurements recorded during hospitalization. AKI was defined based on the K-DIGO guidelines. The primary objective was to analyze the risk factors for mortality.

Results

The cohort included 3,007 patients, with a median age of 54.6 ±14.5 years. Thirty-five percent of patients died; 44.6% developed PI-BUN/Cr ratio and 71.4% AKI. Mortality was associated with older age >60 years [Hazard ratio (HR)]=1.45, 95% CI: 1.28-1.65; p<0.001); male (HR=1.25, 95% CI: 1.09-1.44; p=0.002); and AKI (HR=3.29, 95% CI: 2.42-4.46; p<0.001). PI-BUN/Cr was not associated with mortality (HR=0.95, 95% CI:0.83-1.07; p=0.417). According to the PI-BUN/Cr and AKI status, mortality was higher in the groups with PI-BUN/CR & Non-AKI (HR=2.82, 95% CI: 1.61-4.93; p<0.001); Non-PI-BUN/CR & AKI (HR=5.47, 95% CI: 3.54-8.44; p<0.001); and PI-BUN/CR & AKI (HR=4.26, 95% CI: 2.75-6.62, p<0.001). Survival analysis is shown in Figure 1.

Conclusion

While PI-BUN/Cr alone may not directly associate with mortality, its capacity to phenotype patients according to their AKI status holds significant promise in offering valuable insights into patient prognosis and outcomes.

Funding

  • Government Support – Non-U.S.