Abstract
INTRODUCTION: Patients recovering from severe acute exacerbations of chronic obstructive pulmonary disease (AECOPD) have a 30-day readmission rate of 20%. This study evaluated the feasibility of conducting a randomised controlled trial to evaluate clinical, patient-reported and physiological effects of home high-flow therapy (HFT) in addition to usual medical therapy, in eucapnic patients recovering from AECOPD to support the design of a phase 3 trial. METHODS: A mixed-methods feasibility randomised controlled trial (quantitative primacy, concurrently embedded qualitative evaluation) (ISRCTN15949009) recruiting consecutive non-obese patients hospitalised with AECOPD not requiring acute non-invasive ventilation. Participants were randomised to receive usual care or usual care and home HFT (37°C, 30 L/min) with weekly home-based follow-up for 4 weeks to collect data on: device usage, breathlessness (modified Borg scale, visual analogue scale, Multidimensional Dyspnoea Profile), health-related quality of life (COPD Assessment Test (CAT), Clinical COPD Questionnaire), pulse oximetry, spirometry and inspiratory capacity, parasternal electromyography and actigraphy. Semistructured interviews were conducted in week 4. Trial progression criteria were: ≥40% of eligible patients randomised, ≤20% attrition, ≥70% complete data, and no device-related serious adverse events (SAE). RESULTS: 18 of 45 eligible patients were randomised (age 69±5 years, 44% female, body mass index 23±5 kg/m(2), forced expiratory volume in 1 second 32±12%). One withdrew following non-respiratory hospitalisation. Complete outcome measures were collected in >90% of home assessments. There were no device-related SAE. Daily HFT usage was 2.7±2.2 hours in week 1, falling to 2.3±1.4 hours by week 4. Temperature and flow settings were modified for comfort in 6 cases. Higher HFT usage was associated with lower symptom burden (CAT p=0.01). Interviews highlighted ease of device use, reduced salbutamol usage, and improved sputum production and clearance. CONCLUSIONS: The data from this feasibility study support the progression to a phase 3 randomised clinical trial investigating the effect of home (HFT) on admission-free survival in COPD patients recovering from a severe exacerbation. TRIAL REGISTRATION NUMBER: The study received ethical approval (REC19/LO/0194) and was prospectively registered (ISRCTN15949009).