Acute Kidney Injury in COVID-19: clinical outcomes and risk factors

Abstract Background:Understanding of the incidence and effects of acute kidney injury (AKI) in patients diagnosed with COVID-19 is limited. The purpose of this study was to examine risk factors and related outcomes associated with AKI among patients diagnosed with COVID-19. Method: This is a retrospective cohort study of patients diagnosed with COVID-19 associated-pneumonia admitted to a tertiary hospital in Wuhan between January to February 2020. AKI was defined and staged according to the Kidney Disease: Improving Global Outcome (KDIGO) classification criteria. Cox’s multivariate regression and logistic regression modelling were used to assess the effects of AKI on hospital mortality and risk factors associated with occurrence of AKI. Primary outcomes were risk-adjusted in-hospital mortality.Results:342 patients were finally enrolled in this study. AKI occurred in 13.4% (n = 46), among them 7.0% (n = 24) developed stage 1AKI, and 6.4% (n = 22) developed stage 2 - 3 AKI. Overall 26.9% (n = 92) died during hospitalization. Among them 19.3% (57/296) of the non-AKI patients died, 62.5%(15/24) of stage 1 AKI patients, and 90.9% (20/22) of stage 2 - 3 AKI patients died. AKI was strongly associated with mortality (HR 2.52; 95% CI, 1.59-3.96; p＜0.001). Further analysis shows that progression to AKI stage 2 - 3 doubles the hazard ratio for death. Age, leukocytes number, fibrinogen concentration, C-reative protein level, and severity of pneumonia at admission were independent risk factors associated with the development of AKI. Conclusion:Acute kidney injury is common among hospitalized COVID-19 patients and strongly associated with increased mortality, early detection and prevention of the progression of AKI may be critical to reduce mortality of these patients.