Acute kidney injury in patients with Covid-19 in a Brazilian ICU: incidence, predictors and in-hospital mortality

Introduction: There is little data in the literature on acute kidney injury (AKI) in Covid-19 cases, although relevant in clinical practice in the ICU, especially in Brazil. Our goal was to identify the incidence of AKI, predictive factors and impact on hospital mortality. Method: Retrospective cohort of patients with Covid-19 admitted to the ICU. AKI was defined according to KDIGO criteria. Data was collected from electronic medical records between March 17 and April 26. Results: Of the 102 patients, 55.9% progressed with AKI, and the majority (66.7%) was classified as stage 3. Multivariate logistic regression showed age (RC 1.101; 95% CI 1.026 1.181; p = 0.0070), estimated glomerular filtration rate - eGFR (RC 1.127; 95% CI 1.022 - 1.243; p = 0.0170) and hypertension (RC 3.212; 95% CI 1.065 - 9.690; p = 0.0380) as independent predictors of AKI. Twenty-three patients died. In the group without kidney injury, there were 8.9% deaths, while in the group with AKI, 33.3% of patients died (RR 5.125; 95% CI 1.598 - 16.431; p = 0.0060). The average survival, in days, was higher in the group without AKI. Cox multivariate analysis showed age (RR 1.054; 95% CI 1.014 - 1.095; p = 0.0080) and severe acute respiratory distress syndrome (RR 8.953; 95% CI 1.128 - 71.048; p = 0.0380) as predictors of hospital mortality. Conclusion: We found a high incidence of AKI; and as predictive factors for its occurrence: age, eGFR and hypertension. AKI was associated with higher hospital mortality.