Acute kidney injury in patients with severe COVID-19: clinical course, risk factors, and outcomes in a referral center in Mexico City

Abstract

Objective: Acute kidney injury (AKI) has been associated with adverse outcomes in patients with COVID-19. However, due to resource limitations across various centers, particularly in Latin America, the clinical course of AKI varies widely. Few data have analyzed modifiable risk factors that can reduce in-hospital stay and mortality. Thus, we aimed to determine the factors associated with extended in-hospital stay and mortality. Materials and methods: This is a retrospective cohort study that included clinical/biochemical data of 413 patients with COVID-19 and AKI. Multiple linear regression was used to determine which factors were associated with prolonged in-hospital stay and Cox regression was used to evaluate independent factors for mortality. Results: The mean age of the subjects was 55 ± 15 years, 63.9% were men, 69.7% developed AKI, and mortality was reported by 23.7%. Multiple linear regression showed that older age (β = 0.148, p = 0.002), ferritin (β = 0.13, p = 0.012), and hemoglobin (β = −0.146, p = 0.006) were independently associated with prolonged length of stay. After Cox regression, positive fluid balance (1.029 [1.004-1.054]), mechanical ventilation (5.658 [2.253-5.540]), and dialysis (2.452 [1.436-4.185]) were associated with increased risk for mortality. Conclusions: Age, hemoglobin, and ferritin were associated with prolonged length of stay, but mechanical ventilation, dialysis, and a fluid balance were associated with mortality in AKI and COVID-19.

Keywords

• Acute kidney injury. COVID-19. Positive fluid balance. In-hospital stay. Mortality. Renal replacement therapy.