Impact of Development and Severity of AKI on In-Hospital Outcomes Among Patients With COVID-19

ABSTRACT

Background: Acute kidney injury (AKI) is a common complication of COVID-19 and is associated with poor outcomes. The aim of this study was to describe the incidence of AKI and to compare its clinical impact with other risk factors on the severity and outcomes of hospitalized COVID-19 patients. Method(s) We conducted a retrospective study on patients >= 18 years old who were admitted to our institution with a laboratory-confirmed diagnosis of COVID-19 infection from March 2020 to December 2020. Data on demographics, kidney function prior to and during hospitalization, inflammatory biomarkers, comorbidities, medications, and outcomes including mortality, mechanical ventilation (MV) and renal replacement therapy (RRT) were collect from electronic medical record. Definition and staging of AKI were based on the KDIGO guidelines. Survival and use of MV by AKI and AKI stage was analyzed using Chi-square test;strength of association was measured using correlation coefficients;and significance was assessed at p < 0.05. Result(s) Of 240 inpatients admitted for COVID-19, 153 (63.7%) survived to discharge. A total of 121 (50.4%) patients developed AKI during hospitalization 43.7% stage 1, 34.5% stage 2, and 21.8% stage 3. Almost 1 in 4 patients with AKI (23.1%) required RRT. Fifty-eight (49.2% overall, 37.3%, 51.2%, and 70.8% for AKI stage 1, 2, and 3, respectively) patients with AKI required mechanical ventilation, compared to 15 (13.5%) with normal renal function (p< 0.001). Age, presence of AKI, AKI stage, history of coronary artery disease, and initial lactate dehydrogenase were significantly associated with in-hospital death. Development of AKI (r=0.33, p< 0.001) and AKI stage (r=0.38, p<0.001) were more strongly associated with in-hospital mortality than the remaining bivariate associations. Survival at discharge was strongly associated with renal function, with survival declining from 79.5% among patients with normal renal function to 61.5%, 41.5%, and 30.7% among AKI stage 1, 2, and 3 patients (p <0.001). Conclusion(s) AKI is more strongly associated with increased mortality among patients with COVID-19 infection compared with demographics, comorbidities, and inflammatory biomarkers. Patients with Stage 2-3 AKI are more likely to have greater severity and worse outcomes.