Acute kidney injury in hospitalized COVID-19 patients

Abstract

Background: Acute kidney injury (AKI) in COVID-19 patients is associated with poor prognosis. However, the incidence, risk factors and potential outcomes of AKI in hospitalized patients are not well studied.

Materials and methods: This is a retrospective cohort study conducted in two major university hospitals. Electronic health records of the patients, 18 years or older, hospitalized between 13 April and 1 June 2020 with confirmed COVID-19 were reviewed. We described the incidence and the risk factors for AKI development in COVID-19 patients. Furthermore, we investigated the effects of AKI on the length of hospital and intensive care unit (ICU) stay, the admission rates to ICU, the percentage of patients with cytokine storm and in-hospital mortality rate.

Results: Among 770 hospitalized patients included in this study, 92 (11.9%) patients developed AKI. The length of hospitalized days (16 vs 9.9, p < 0.001) and days spent in the hospital until ICU admission (3.5 vs. 2.5, p = 0.003) were higher in the AKI group compared to patients without AKI. In addition, ICU admission rates were also significantly higher in patients with AKI (63% vs. 20.7%, p < 0.001). The percentage of patients with AKI who developed cytokine storm was significantly higher than patients without AKI (25.9% vs. 14%, p = 0.009). Furthermore, the in-hospital mortality rate was significantly higher in patients with AKI (47.2% vs. 4.7%, p < 0.001).

Conclusions: AKI is common in hospitalized COVID-19 patients. Furthermore, we show that AKI increases the admission rates to ICU and in-hospital mortality. Our findings suggest that AKI should be effectively managed to prevent the adverse outcomes in COVID-19 patients.

Keywords: Acute kidney injury; COVID-19; Hospital stay; Mortality.