Effect of high-flow nasal therapy during acute aerobic exercise in patients with chronic obstructive pulmonary disease after exacerbation: protocol for a randomised, controlled, cross-over trial.

INTRODUCTION: Early pulmonary rehabilitation is recommended after a severe exacerbation of chronic obstructive pulmonary disease (COPD). However, this is difficult to implement, particularly for exercise training. High-flow nasal therapy (HFNT) may reduce the work of breathing and dyspnoea and may improve exercise tolerance.

METHODS AND ANALYSIS: This is a single-centre, prospective, controlled, randomised, cross-over study. Eligible patients will have a diagnosis of COPD (postbronchodilator forced expiratory volume in 1 s/forced vital capacity ratio of <0.7). Two constant work rate exercise tests at 80% of the peak work rate will be carried out on two consecutive days with and without HFNT. The primary outcome will be the difference in endurance time between the two conditions. Secondary outcomes will be the change in muscle oxygenation during exercise, dyspnoea and muscle fatigue, respiratory muscle strength after exercise, respiratory rate, cardiac frequency, transcutaneous CO2 pressure and pulsed O2 saturation. Nineteen patients will be included. Data will be analysed as intention to treat by a blinded statistician.

ETHICS AND DISSEMINATION: Ethics approval has been obtained from the Ethics Committees Nord-Ouest III, Caen, France (N° ID RCB: 2016-A01325-46). The study will begin in April 2017 for a duration of 2 years. The results of the trial will be presented at national and international meetings and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER: NCT03058081.