Effects of early and late continuous renal replacement therapy on intensive care unit mortality in patients with COVID-19 with acute respiratory distress syndrome and acute kidney injury: a comparative study

Abstract Introduction Acute kidney injury (AKI) is linked to disease severity and prognosis in patients with coronavirus disease 2019 (COVID-19), and mortality increases even with milder stages. This study primarily investigated the effects of continuous renal replacement therapy (CRRT) timing on intensive care unit (ICU) mortality in patients with COVID-19 with acute respiratory distress syndrome (ARDS) and AKI. Secondary goals were secondary goals for the ICU, days without life support treatment, and change in post-CRRT day biomarker levels, the length of ICU and overall hospital stay. Methods In this retrospective study, patients with COVID-19 with ARDS and AKI were divided into CRRT initiated at AKI stages 1 and 2, early-CRRT (E-CRRT) and AKI stage 3, late-CRRT (L-CRRT) and followed until discharge or death. Results E-CRRT had 20 patients and L-CRRT had 18 patients. No association between CRRT timing and ICU mortality was detected (p = 0.724). Moreover, the timing was not associated with ICU, total hospital stay, or days without life support treatment. However, it was associated with D-dimer levels for both groups and ferritin and C-reactive protein (CRP) levels for E-CRRT. There were no associations for other markers, such as procalcitonin, troponin T, pro-brain natriuretic peptide (pro-BNP), interleukin-6, fibrinogen, or antithrombin III levels. Conclusions CRRT timing was not associated with ICU mortality, total hospital stay, or days without life support treatment in this cohort. For E-CRRT, ferritin and CRP levels, and for both groups, D-dimer levels, were associated with CRRT timing. Randomized controlled trials are needed to examine the effects of CRRT timing in patients with COVID-19 with ARDS and AKI.