Acute kidney injury in hospitalized patients with COVID-19: A Portuguese cohort

INTRODUCTION: The incidence of acute kidney injury (AKI) in coronavirus disease 2019 (COVID-19) patients ranges from 0.5% to 35% and has been associated with worse prognosis. The purpose of this study was to evaluate the incidence, severity, duration, risk factors and prognosis of AKI in hospitalized patients with COVID-19. METHODS: We conducted a retrospective single-center analysis of 192 hospitalized COVID-19 patients from March to May of 2020. AKI was diagnosed using the Kidney Disease Improving Global Outcome (KDIGO) classification based on serum creatinine (SCr) criteria. Persistent and transient AKI were defined according to the Acute Disease Quality Initiative (ADQI) workgroup definitions. RESULTS: In this cohort of COVID-19 patients, 55.2% developed AKI (n = 106). The majority of AKI patients had persistent AKI (n = 64, 60.4%). Overall, in-hospital mortality was 18.2% (n = 35) and was higher in AKI patients (28.3% vs. 5.9%, p < 0.001, unadjusted OR 6.03 (2.22–16.37), p < 0.001). In this multivariate analysis, older age (adjusted OR 1.07 (95% CI 1.02–1.11), p = 0.004), lower Hb level (adjusted OR 0.78 (95% CI 0.60–0.98), p = 0.035), duration of AKI (adjusted OR 7.34 for persistent AKI (95% CI 2.37–22.72), p = 0.001) and severity of AKI (adjusted OR 2.65 per increase in KDIGO stage (95% CI 1.32–5.33), p = 0.006) were independent predictors of mortality. CONCLUSION: AKI was frequent in hospitalized patients with COVID-19. Persistent AKI and higher severity of AKI were independent predictors of in-hospital mortality.