A randomised controlled trial of non-invasive ventilation compared with extracorporeal carbon dioxide removal for acute hypercapnic exacerbations of chronic obstructive pulmonary disease.

Background: Patients presenting with acute hypercapnic respiratory failure due to exacerbations of chronic obstructive pulmonary disease (AECOPD) are typically managed with non-invasive ventilation (NIV). The impact of low-flow extracorporeal carbon dioxide removal (ECCOR) on outcome in these patients has not been explored in randomised trials.

Methods: Open-label randomised trial comparing NIV (NIV arm) with ECCOR (ECCOR arm) in patients with AECOPD at high risk of NIV failure (pH < 7.30 after ≥ 1 h of NIV). The primary endpoint was time to cessation of NIV. Secondary outcomes included device tolerance and complications, changes in arterial blood gases, hospital survival.

Results: Eighteen patients (median age 67.5, IQR (61.5-71) years; median GOLD stage 3 were enrolled (nine in each arm). Time to NIV discontinuation was shorter with ECCOR (7:00 (6:18-8:30) vs 24:30 (18:15-49:45) h, p = 0.004). Arterial pH was higher with ECCOR at 4 h post-randomisation (7.35 (7.31-7.37) vs 7.25 (7.21-7.26), p < 0.001). Partial pressure of arterial CO (PaCO) was significantly lower with ECCOR at 4 h (6.8 (6.2-7.15) vs 8.3 (7.74-9.3) kPa; p = 0.024). Dyspnoea and comfort both rapidly improved with commencement of ECCOR. There were no severe or life-threatening complications in the study population. There were no episodes of major bleeding or red blood cell transfusion in either group. ICU and hospital length of stay were longer with ECCOR, and there was no difference in 90-day mortality or functional outcomes at follow-up.

Interpretation: There is evidence of benefit associated with ECCOR with time to improvement in respiratory acidosis, in respiratory physiology and an immediate improvement in patient comfort and dyspnoea with commencement of ECCOR. In addition, there was minimal clinically significant adverse events associated with ECCOR use in patients with AECOPD at risk of failing or not tolerating NIV. However, the ICU and hospital lengths of stay were longer in the ECCOR for similar outcomes. Trial registration The trial is prospectively registered on ClinicalTrials.gov: NCT02086084. Registered on 13th March 2014, https://clinicaltrials.gov/ct2/show/NCT02086084?cond=ecco2r&draw=2&rank=8.