Relationship of lung oxygenation to timing of hemoadsorption therapy initiation in COVID-19 patients requiring extracorporeal mechanical oxygenation (ECMO): an observational analysis from the CytoSorb therapy in COVID-19 (CTC) Registry

ABSTRACT

Introduction: The multicenter CTC Registry study collected patientlevel data in COVID-19 patients receiving CytoSorb therapy under FDA Emergency Use Authorization. An earlier report on the first 52 CTC patients on ECMO treated with CytoSorb showed 69% overall survival [1]. The current analysis focuses on changes in pulmonary function relative to the time of CytoSorb therapy. Methods: A total of 56 patients from 5 U.S. centers were included. Data on demographics, mechanical ventilation (MV), ECMO, and arterial blood gases during CytoSorb therapy were analyzed. Linear regression was used to evaluate the relationship between the timing of initiation of CytoSorb therapy to lung oxygenation according to changes in PaO2/FiO2 ratio. Results: In the current analysis, 71% (40/56) overall survival was observed. For these survivors, time to CytoSorb start after ICU admission, MV start, and ECMO start was 138 ± 171.3 h, 83 ± 111.0 h, and 55 ± 156.5 h, respectively, with mean duration of CytoSorb therapy of 83 ± 29.1 h. At the first 24 h following CytoSorb therapy, oxygenation was improved evidenced by decreased MV FiO2 and ECMO FdO2 requirements and an increased PaO2/FiO2 ratio (90.2 ± 58.13 mmHg to 166.3 ± 98.67 mmHg, p < 0.001, N = 21). Linear regression analysis suggested that earlier initiation of CytoSorb therapy following ICU admission may be correlated to greater improvements in PaO2/FiO2 ratio (r = -0.37, p = 0.103), however, this trend did not achieve statistical significance. Conclusions: High survival rates have been observed with adjunct CytoSorb therapy in critically ill COVID-19 patients on ECMO. The current analysis suggests that early initiation of hemoadsorption following ICU admission may contribute to earlier improvements in native lung oxygenation.