Regional Citrate and Systemic Heparin Are Adequate to Maintain Filter Half-Life for COVID-19 Patients on CRRT

Background: The aim of our study is to compare clotting of CRRT filters in patients with COVID-19-associated AKI vs. septic shock-associated AKI. Methods: Retrospective single center study of adult patients with COVID-19 infection compared to those with septic shock admitted to the ICU at a tertiary university hospital April-October 2020. We used independent t-test and chi square test to determine statistical significance of CRRT filter clotting and related factors in COVID-19 patients compared with septic shock patients in the ICU. Time to event data was analyzed with Kaplan-Meier curves. Analyses were performed on Microsoft Excel and MedCalc. Results: A total of 27 ICU patients with AKI requiring CRRT were included in the study, 13 with COVID-19 infection and 14 with septic shock. The mean half-life of CRRT hemofilter was similar in COVID-19 patients compared to non-COVID-19 patients (27.4 hours vs 27.5 hours, p=0.79). The number of CRRT hemofilter changes per day were also similar in both groups (0.6 filter changes per day, p=0.84) (fig. 1). However, However, significantly more patients with COVID-19 were on systemic heparin compared to the non-COVID-19 patients (69% vs 13%, p= 0.02) (fig. 2). Conclusions: We found that COVID-19 patients with AKI requiring CRRT had similar CRRT hemofilter half-life compared with sepsis-associated AKI patients with use of regional citrate anticoagulation and systemic heparin use. Further studies are needed to find which methods of anticoagulation is optimal in patients with COVID-19 infection with AKI requiring CRRT.