Analysis of Renal Function in Patients Hospitalized with COVID19

ABSTRACT

Introduction: COVID19 was originally thought to be solely a respiratory disease, however, other organs, such as the kidneys, are often also affected. While acute kidney injury (AKI) and augmented renal clearance (ARC) have both been documented, the incidence, renal characteristics, and outcome of each derangement have not been fully elucidated. Research Question or Hypothesis: What are the incidences, characteristics, and outcomes of AKI, ARC, and no AKI/ARC in patients hospitalized with COVID19? Study Design: Retrospective, observational cohort study Methods: Inpatient data from the National COVID Cohort Collaborative database with laboratory confirmed COVID19 who were >18 years old were utilized. Patients who had all data to calculate creatinine clearance (CrCl) via Cockcroft-Gault equation were screened. Exclusion criteria were pregnancy, body mass index <18kg/m2, history of end-stage renal disease on dialysis or nephrectomy. Episodes of AKI and ARC were defined using AKIN criteria and CrCl >130mL/min, respectively. Renal function characteristics and outcomes included days with episode, hospital length of stay (LOS), and mortality. Descriptive statistics and Mann-Whitney U tests were used for statistical analysis where appropriate with p<0.05 indicating statistical significance. Result(s) 15,608 patients from 11 sites were included. Overall, 57.3% were male with median age 62.7[50.1-73.2] years. The incidence of No AKI/ARC, AKI, and ARC was 43.5%, 22.9%, and 33.6%, respectively. Episodes of ARC lasted longer than AKI (4[2-7] vs 3[1-6] days;p<0.0001) Patients with AKI and ARC both had longer LOS compared to no AKI/ARC (19[10-34] and 6[4-11] vs 6[4-10];p<0.001). Patients with AKI had the highest mortality followed by no AKI/ARC then ARC (41.7% vs 10.1% vs 5.4%;p<0.001). Conclusion(s) A significant proportion of patients with COVID19 exhibit altered renal function throughout hospitalization. Clinicians should be mindful of these alterations given their associations with increased LOS and mortality with AKI. Future research should explore the impact of ARC on medication therapy in patients with COVID19.