Introduction: COVID-19 is characterised by hyperinflammation and coagulopathy. Severe cases often develop respiratory distress, requiring mechanical ventilation and critical cases progressing to ARDS. Control of hyperinflammation has been proposed as a possible therapeutic avenue for COVID-19; extracorporeal blood purification (EBP) modalities offer an attractive mean to ameliorate maladaptive inflammation.
With this work, we describe the longitudinal variation of parameters of systemic inflammation in critically ill COVID-19 patients treated with blood purification using AN69ST (oXiris) hemodiafilter.
Methods: We performed a time-series analysis of 44 consecutive COVID-19 cases treated with the AN69ST (oXiris) cytokine adsorbing hemodiafilter; we visualise longitudinal results of biochemical, inflammatory, blood gas- and vital sign parameters.
Results: Blood purification was indicated for suspected hyperinflammation or hypercoagulation, (= CRP > 100 mg/L and/or IL-6 > 40 pg/mL and/or Ferritin > 500 ng/mL and/or Lactate Dehydrogenase > 365 U/L or D-dimers > 2000 ng/mL).
All patients were treated with at least 1 cycle extracorporeal continuous venovenous hemofiltration (CVVHF) with cytokine adsorbing hemodiafilter (CAH); of these, 30 severe patients received CVVHF-CAH within 4 - 12 hours of hospitalisation. Another 14 patients admitted with mild-to-moderate symptoms progressed to severe disease and placed on EBP during the course of hospitalisation. The treatment was associated with a reduction of Ferritin, C-reactive protein, Fibrinogen, several inflammatory markers and a resolution of numerous cytopenias. The observed mortality across the cohort was 36.3% across the cohort.
Conclusion: Extracorporeal blood purification with cytokine adsorbing hemofilter was associated with a decrease in the acute phase proteins CRP, Ferritin, and resolution of numerous cytopenias. Repetitive hemofiltration has been associated with lower levels of IL-6 in COVID-19 patients.