ACUTE KIDNEY INJURY AS A MARKER OF DISEASE SEVERITY AND IN-HOSPITAL MORTALITY IN CRITICALLY ILL PATIENTS WITH COVID-19:

Abstract

Acute kidney injury (AKI) is a frequent complication in severe coronavirus disease 2019 (COVID-19) and is closely associated with critical illness and poor outcomes. However, its role as an independent predictor of mortality in critically ill patients remains uncertain. This retrospective cohort study included critically ill patients with confirmed COVID-19 admitted to a referral intensive care unit between May 2020 and December 2021. After data cleaning and deduplication, 230 patients were analyzed. The primary outcome was in-hospital mortality. AKI status was obtained from the original clinical database. Comparisons were performed using bivariate analyses, and a multivariable logistic regression model was fitted to identify factors independently associated with mortality. The adjusted model was performed using complete-case analysis and included 182 patients, with 48 excluded because of missing data in at least one model covariate. AKI occurred in 88 patients (38.3%), and overall in-hospital mortality was 74.8%. Patients with AKI had worse laboratory profiles and required more frequent organ support, including mechanical ventilation, noradrenaline, and hemodialysis. In the adjusted analysis (n = 182), older age (OR 1.04; 95% CI 1.01–1.08; p = 0.011) and mechanical ventilation (OR 19.38; 95% CI 4.90–95.14; p < 0.001) were independently associated with in-hospital mortality, whereas AKI was not independently associated with death. In critically ill patients with COVID-19, AKI identified a subgroup with greater clinical severity, higher need for organ support, and markedly increased crude mortality. However, after adjustment for markers of disease severity, particularly mechanical ventilation, AKI did not remain independently associated with death. The main contribution of this study is to show that, in this setting, AKI should be interpreted predominantly as a marker of multisystem failure rather than as an isolated independent determinant of in-hospital mortality.