AKI in Hospitalized Patients with COVID-19

Abstract

Background: Early reports indicate that AKI is common among patients with coronavirus disease 2019 (COVID-19) and associated with worse outcomes. However, AKI among hospitalized patients with COVID-19 in the United States is not well described.

Methods: This retrospective, observational study involved a review of data from electronic health records of patients aged ≥18 years with laboratory-confirmed COVID-19 admitted to the Mount Sinai Health System from February 27 to May 30, 2020. We describe the frequency of AKI and dialysis requirement, AKI recovery, and adjusted odds ratios (aORs) with mortality.

Results: Of 3993 hospitalized patients with COVID-19, AKI occurred in 1835 (46%) patients; 347 (19%) of the patients with AKI required dialysis. The proportions with stages 1, 2, or 3 AKI were 39%, 19%, and 42%, respectively. A total of 976 (24%) patients were admitted to intensive care, and 745 (76%) experienced AKI. Of the 435 patients with AKI and urine studies, 84% had proteinuria, 81% had hematuria, and 60% had leukocyturia. Independent predictors of severe AKI were CKD, men, and higher serum potassium at admission. In-hospital mortality was 50% among patients with AKI versus 8% among those without AKI (aOR, 9.2; 95% confidence interval, 7.5 to 11.3). Of survivors with AKI who were discharged, 35% had not recovered to baseline kidney function by the time of discharge. An additional 28 of 77 (36%) patients who had not recovered kidney function at discharge did so on posthospital follow-up.

Conclusions: AKI is common among patients hospitalized with COVID-19 and is associated with high mortality. Of all patients with AKI, only 30% survived with recovery of kidney function by the time of discharge.

Keywords: COVID-19; acute renal failure; clinical nephrology; dialysis.

Graphical abstract

Figure 1.

AKI requiring dialysis was common and varied by need for ICU admimssion. While 19% of patients overall required dialysis, 32% of patients who were admitted to the ICU required dialysis.

Figure 2.

Approximately a third of patients did not have renal recovery at discharge or post-hospitalization follow up. Proportion of patients with AKI stratified by recovery versus nonrecovery at discharge and discharge follow-up. Recovery of kidney function was stratified into recover and AKD defined as (1) recovery: difference in creatinine is ≤0.3 and creatinine change in percentage is ≤25%; (2) stage 1: difference in creatinine is >0.3 and creatinine change in percentage is ≤25% or creatinine change in percentage is >25% and ≤100%; (3) stage 2: creatinine change in percentage is >100% and ≤200%; and (4) stage 3: creatinine change in percentage is >200% or requiring dialysis 72 hours prior to discharge.

Figure 3.

Trajectory of creatinine during the first 14 days of hospitalizations in patients who were discharged by recovery and nonrecovery which demonstrate the severity and prolonged nature of the AKI. We used local regression (loess) for smoothening creatinine values across the interval of 2 weeks posthospital admission to visualize trajectories by AKD category.

Figure 4.

Survival probability is lower in patients with AKI. Kaplan–Meier survival curves for patients with and without AKI. Red line indicates patients with AKI, and blue line is for those without AKI. All patients were censored at 30 days. Patients who were discharged alive before 30 days were treated as still at risk and not censored at discharge.