Low flow extracorporeal CO2 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 (ECCO2R). Methods: This was a prospective pilot study, using the Abylcap (R) (Bellco) ECCO2R, with crossover off-on-off design (2-h blocks) under stable MV settings, and follow up till end of ECCO2R. 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/FiO(2) = 5 cmH(2)O, FiO(2) titrated to SaO(2) 88-95%, plateau pressure >= 28 cmH(2)O, and respiratory acidosis (pH < 7.25). Results: After 2-h of ECCO2R, 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). ECCO2R was hemodynamically well tolerated. During the whole period of ECCO2R, 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 ECCO2R significantly reduced PaCO2 after 2 h, Follow up during the entire ECCO2R period revealed a high incidence of bleeding and circuit thrombosis