A mixed-methods pilot study of domiciliary nasal high-flow therapy for breathlessness in people with chronic obstructive pulmonary disease who do not qualify for domiciliary long-term oxygen therapy.

Background: High-flow nasal oxygen (HFNO) therapy delivers humidified, heated air with flow rates of up to 60 L/min with oxygen entrained. HFNO has advantages over conventional oxygen therapy, including precise and reliable fraction of inspired oxygen delivery, therefore is recommended as first-line treatment for people with acute hypoxaemic respiratory failure.

Objectives: This pilot study aimed to determine the feasibility and acceptability of domiciliary nasal high flow (NHF) without entrained oxygen for people with chronic obstructive pulmonary disease (COPD) and severe breathlessness.

Design: Single-arm, mixed-methods, pilot study of an 8-day, air-only NHF intervention in adults with COPD and severe breathlessness not requiring domiciliary oxygen therapy.

Methods: Participants were educated and advised to use NHF for ⩾7 h per night for 7 nights with day use as desired. Patient-reported outcome measures were assessed on Days 3, 5 and 8.

Primary outcome: feasibility.

Secondary outcomes: breathlessness (dyspnoea), fatigue, quality of life, physical function, sleep, tolerability and safety. Acceptability was also assessed through semi-structured interviews.

Results: Fifteen participants were enrolled (mean age 73.6; 40% women; mean FEV₁ 41% predicted, mean DLCO 43.0% predicted; mean modified Medical Research Council score 3.7). Thirteen (87%) completed the trial, with 8 (54%) keeping the device at the end of the trial and 3 (20%) continuing use long-term. Adherence varied, with average daily usage higher amongst participants who kept the device compared to those who returned it (6.8 h ± 2.3 h vs 3.4 h ± 3.7 h). No changes in worst breathlessness (mean = 0.7, SD = 1.2, p = 0.109), dyspnoea mastery (mean = 0.3, SD = 0.6, p = 0.176) or fatigue (mean = 0.0, SD = 2.4, p = 1.00) were observed at Day 8 compared to baseline. No significant adverse events were reported. Qualitative interviews demonstrated subjective improvements in breathlessness, dry mouth and sputum production for some participants, whilst others found NHF uncomfortable. Fear of NHF dependence and concerns regarding long-term running costs were reported.

Conclusion: Domiciliary NHF was a feasible intervention, albeit with varied adoption and acceptability. These trial implementation outcomes may have affected preliminary effectiveness outcomes. Further research is required to determine what role domiciliary NHF may have for people with COPD and severe breathlessness.

Trial registration: ACTRN12621000044820.