Comparison of mortality in hospitalized COVID-19 Patients with AKI vs. ESRD

ABSTRACT

Background: Patients hospitalized with COVID-19 illness are at high risk for developing acute kidney injury (AKI) and have high mortality rates. Chronic kidney disease (CKD) and end stage renal disease (ESRD) are independent risk factors for COVID-19 disease severity and mortality. Our study compares mortality rates of hospitalized patients with COVID-19 illness who 1) develop AKI with baseline normal renal function, 2) develop AKI with baseline moderate-to-severe CKD stages 3 or 4, and 3) have ESRD. Methods: Consecutive patients admitted with COVID-19 illness referred to Nephrology with AKI or ESRD on dialysis were included. Retrospective data collected included Demographics, medical history including CKD stage, labs, O2 therapy, AKI diagnosis (KDIGO), and renal replacement therapy (RRT). Chi-square test was used to evaluate the unadjusted association between CKD stage and mortality. Multivariate logistic regression models were constructed to estimate associations between CKD stage and mortality adjusting for potential confounders. Results: 166 patients were analyzed 87 patients had AKI with baseline normal renal function (GFR > 60 ml/min (AKI-N), 41 patients had AKI on CKD Stage 3 or 4 (AKI-CKD3/4), and 38 patients had ESRD. Mechanical ventilation was used in 33[37.9%] AKI-N, 20[48.8%] AKI-CKD3/4, and 10[26.3%] ERSD patients, p = 0.069. Three [3.5%] AKI-N received iHD, and 9[10.3%] received CRRT/PIRRT. Six [14.6%] AKI-CKD3/4 received iHD and 7[17.1%] received CRRT/PIRRT. Of all AKI patients, 55.5% had Stage 3 AKI. 34[89.5%] ESRD patients received iHD and 2[5.3%] received PD. AKICKD3/ 4 were more likely to receive RRT than AKI-N, p = 0.035. Death occurred in 36[41.4%] AKI-N, 26[63.4%] AKI-CKD3/4, and 9[23.7%] ESRD patients, (p=0.001). Multivariate logistic regression modeling for mortality accounting for age, race, gender, diabetes mellitus, hypertension, obesity, and CHF revealed increased odds of mortality for AKI-CKD3/4 (OR=2.59, p=0.006) and decreased odds of mortality for ESRD patients (OR=0.5, p=0.001), compared to AKI-N. Conclusions: COVID-19 patients with ESRD had less mortality than AKI-N, while AKI-CKD3/4 had higher mortality than both ESRD and AKI-N patients. Prospective studies to determine specific criteria for early initiation of RRT in COVID-19 AKI patients are warranted, as it may decrease mortality especially in those with baseline CKD 3/4.