Low flow extracorporeal CO 2 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 CO2 removal (ECCO2 R).

METHODS: This was a prospective pilot study, using the Abylcap® (Bellco) ECCO2 R, with crossover off-on-off design (2-h blocks) under stable MV settings, and follow up till end of ECCO2 R. Primary endpoint for effectiveness was a 20% reduction of PaCO2 after the first 2-h. Adverse events (AE) were recorded prospectively. We included 10 ARDS patients on MV, with PaO2 /FiO2  < 150 mmHg, tidal volume ≤ 8 mL/kg with positive end-expiratory pressure ≥ 5 cmH2 O, FiO2 titrated to SaO2 88-95%, plateau pressure ≥ 28 cmH2 O, and respiratory acidosis (pH <7.25).

RESULTS: After 2-h of ECCO2 R, 6 patients had a ≥ 20% decrease in PaCO2 (60%); PaCO2 decreased 28.4% (from 58.4 to 48.7 mmHg, p = 0.005), and pH increased (1.59%, p = 0.005). ECCO2 R was hemodynamically well tolerated. During the whole period of ECCO2 R, 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 ECCO2 R significantly reduced PaCO2 after 2 h, Follow up during the entire ECCO2 R period revealed a high incidence of bleeding and circuit thrombosis.

TRIAL REGISTRATION: https://clinicaltrials.gov identifier: NCT01911533 , registered 23 July 2013.