Effect of high-flow nasal therapy during exercise training in COPD patients with chronic respiratory failure: study protocol for a randomised controlled trial

Abstract Background The benefit of pulmonary rehabilitation (PR) in symptomatic chronic obstructive pulmonary disease (COPD) is well known. However, advanced patients with chronic respiratory failure (CRF), a category excluded from most studies, are frequently unable to sustain a work-load sufficiently high to obtain the full benefit of PR on exercise tolerance. Recent studies involving heated and humidified high flow oxygen therapy (HFOT) showed positive effects on breathing pattern and ventilatory efficiency during effort. We thus plan to compare, in COPD patients with CRF undergoing a high-intensity exercise programme, the effect of using HFOT versus standard oxygen delivery via Venturi Mask (V-mask), at the same inspiratory oxygen fraction, on improving exercise endurance. Methods/Design This is a multicentre randomised controlled trial that will involve 156 COPD inpatients with CRF recruited from seven PR hospitals. Patients will be randomised to one of two groups – V-mask versus HFOT. All patients will undergo the same high-intensity exercise programme using either of the oxygen delivery devices as per their group allocation. Training will consist of 20 sessions, over 1 month (5 sessions per week) within the hospitalisation period. Anthropometric and clinical data, including body mass index, diagnosis, spirometry and comorbidities (Cumulative Rating Scale) will be collected at baseline. At baseline and at the end of the exercise programme (primary assessment time) evaluation will include exercise tolerance (Constant Work Rate Exercise Test) (primary outcome), functional capacity (6-min walk test), maximal inspiratory pressure/maximal expiratory pressure, peripheral muscle strength (biceps and quadriceps) by manual dynamometer, respiratory exchanges (blood gases analysis), disability (Barthel Index and Barthel Dyspnoea Index), impact of disease (COPD Assessment test), and quality of life (Maugeri Respiratory Failure Scale-26). At the end of the training period, patient satisfaction will be evaluated. Discussion This study will add knowledge about the exercise response in advanced COPD with CRF and verify if an alternative tool, namely HFOT, can increase the benefit obtained from PR. Trial registration ClinicalTrials.gov ID NET03322787 Registered: 6 November 2017