High flow nasal oxygen versus usual care in improving pulmonary rehabilitation outcomes of chronic obstructive pulmonary disease patients after an exacerbation - a pilot randomized controlled trial

Introduction Early pulmonary rehabilitation (PR) is guideline-recommended for all chronic obstructive pulmonary disease (COPD) patients post-hospitalization for COPD exacerbation but many patients experience difficulties participating in early PR due to significant breathlessness. High flow nasal oxygen (HFO) has been shown to improve ventilatory efficiency in stable COPD patients, but there is little data on HFO use during exercise training in PR post-COPD exacerbation. Methods We conducted a pilot randomized controlled trial (RCT) to explore the feasibility of a prospective large-scale RCT to evaluate the impact of HFO in improving PR outcomes of COPD patients post-exacerbation. Patients recently hospitalized for COPD exacerbation were enrolled and randomized to either HFO or usual care during an early 6-weeks, outpatient PR program. Results Twenty two patients were randomized between May 2019 to Dec 2019 and 18 patients completed the study. The HFO arm achieved a greater improvement in exercise capacity than the usual care arm, with the mean difference in 6-min walk distance (6MWD) being 30 m (95% CI: −23 m to 84 m), although this was not statistically significant. All 18 patients in both arms were compliant to the pulmonary rehabilitation program (defined by attending ≥75% of exercise sessions). HFO was well tolerated with no adverse events reported. Conclusion This pilot RCT has shown preliminary evidence of the feasibility and high patient acceptability of HFO during early PR on improving exercise capacity in COPD patients post-exacerbation These promising results would justify a larger RCT to confirm HFO’s benefits and has the potential to change PR practice.