Physiological Assessment of ECCO2R on the Work of Breathing in Exacerbations of COPD

The impact of extracorporeal carbon dioxide removal (ECCO2R) on work of breathing and aeration in exacerbations of chronic obstructive pulmonary disease (AECOPD) is poorly understood. The study explores the impact of non-invasive ventilation (NIV) and ECCO2R on respiratory drive, effort and distribution of ventilation in AECOPD. Patients enrolled in a randomised controlled study of the addition of ECCO2R to NIV compared with NIV underwent oesophageal pressure measurement, electrical impedance tomography and parasternal electromyography. 18 patients were enrolled, nine in each arm. Of these, eight in the NIV arm and seven in the ECCO2R arm underwent physiological assessment. Patients randomised to ECCO2R, had a period of NIV combined with ECCO2R and, after removal of NIV, a period of ECCO2R alone. The removal of NIV whilst remaining on ECCO2R resulted in a respiratory acidosis (pH 7.34 (7.31–7.34) vs. 7.31 (7.31–7.34), p p p = 0.0005). On day 1, the work of breathing was lower in the NIV than the ECCO2R group (4.38 (2.76–7.27) vs. 8.03 (4.8–15.94) J/min, p p p = 0.5556). The combination of NIV and ECCO2R results in lower work of breathing and improved neuro-ventilatory coupling. NIV fully supports ventilation early whilst ECCO2R improves neuro-ventilatory coupling and work of breathing over time. Clinicaltrials.gov; NCT02086084; registered 1 December 2015; https://clinicaltrials.gov/study/NCT02086084?cond=copd&term=ecco2r&rank=4