Therapeutic plasma exchange followed by convalescent plasma transfusion in severe and critically ill COVID-19 patients: A single centre non-randomized controlled trial.

Therapeutic plasma exchange (TPE) has been proposed as a rescue therapy in critically ill COVID-19 patients. The aim of the present study was to determine whether combining TPE with convalescent plasma (CVP) transfusion early in the intensive care unit (ICU) stay improves survival among this heterogeneous population. The primary endpoint was survival at 30 days. Secondary endpoints included assessing the evolution of biomarkers, such as the partial pressure of arterial oxygen to fractional inspired oxygen ratio, and C reactive protein (CRP), lactate dehydrogenase (LDH) and ferritin levels at the 7-day follow-up. This single centre, prospective, non-randomized controlled trial was conducted in an 8-bed COVID-19 ICU and included patients with severe COVID-19 pneumonia requiring intensive care treatment. A total of 19 patients were treated by performing TPE followed by CVP transfusion, in addition to standard treatment, while for another 19 patients, only standard treatment according to hospital protocols was used. TPE was initiated during the first 24 h after ICU admission, followed immediately by transfusion of CVP. Survival at 30 days was 47.37% in the TPE CVP group and 26.32% in the control group (P=0.002). Patients in the TPE CVP group also showed better oxygenation and a reduction in inflammation, with decreased CRP, LDH and ferritin levels compared with those in the control group. Overall, the study indicated that early initiation of TPE followed by CVP transfusion may be a valid rescue therapy in severe and critically ill COVID-19 patients, with a statistically significant survival benefit, improved oxygenation and a reduction in inflammatory markers. The trial was registered in the ClinicalTrials.gov database (trial registration number: NCT04973488) on July 22, 2021 (retrospectively registered).