Low flow extracorporeal CO removal in ARDS patients: a prospective short-term crossover pilot study.

Background: Lung protective mechanical ventilation (MV) is the corner stone of therapy for ARDS. However, its use may be limited by respiratory acidosis. This study explored feasibility of, effectiveness and safety of low flow extracorporeal CO removal (ECCOR).

Methods: This was a prospective pilot study, using the Abylcap® (Bellco) ECCOR, with crossover off-on-off design (2-h blocks) under stable MV settings, and follow up till end of ECCOR. Primary endpoint for effectiveness was a 20% reduction of PaCO after the first 2-h. Adverse events (AE) were recorded prospectively. We included 10 ARDS patients on MV, with PaO/FiO < 150 mmHg, tidal volume ≤ 8 mL/kg with positive end-expiratory pressure ≥ 5 cmHO, FiO titrated to SaO 88-95%, plateau pressure ≥ 28 cmHO, and respiratory acidosis (pH <7.25).

Results: After 2-h of ECCOR, 6 patients had a ≥ 20% decrease in PaCO (60%); PaCO decreased 28.4% (from 58.4 to 48.7 mmHg, p = 0.005), and pH increased (1.59%, p = 0.005). ECCOR was hemodynamically well tolerated. During the whole period of ECCOR, 6 patients had an AE (60%); bleeding occurred in 5 patients (50%) and circuit thrombosis in 3 patients (30%), these were judged not to be life threatening.

Conclusions: In ARDS patients, low flow ECCOR significantly reduced PaCO after 2 h, Follow up during the entire ECCOR period revealed a high incidence of bleeding and circuit thrombosis.

Trial Registration: https://clinicaltrials.gov identifier: NCT01911533 , registered 23 July 2013.