Effect of high flow oxygen on exercise capacity in patients with interstitial lung diseases during an exercise test on a bicycle compared with the effect obtained using low flow oxygen

INTERVENTION: RECRUITMENT, CONSENT AND SCREENING: all Patients affected with interstitial lung diseases referred to the physiotherapy department to receive pulmonary rehabilitation in the Lothian region will be invited by a member of the direct care team to participate and will receive a patient’s information sheet with an invitation to attend pre‐assessment for this study. Patients will be given more than 24 hours to consider participation in the study, signing the informed consent. At pre‐assessment, the study will be explained to them and written informed consent will be obtained from those agreeing to participate. RANDOMISATION: following confirmation of eligibility by the CI or PI and signature of the informed consent, patients will be randomised using sealed letters to HFNO or nasal cannula. Patients will be sequentially randomised. Randomisation code and sealing of envelopes will be done by the research nurse and stored in a room at Royal Infirmary of Edinburgh (RIE) accessible with a key. BLINDING: in this open label study patients will not be blinded in respect to the modality of oxygen delivery but will not know the dose of oxygen they will be receiving or their SpO2 during the tests. INTERVENTION: the intervention consists of supplemental oxygen delivered via HFNO at 37°C. Patients that find too warm this temperature can receive HFNO at 34°C. HFNO has a humidifier that saturates the gas mixture at temperature of 31 to 37 C. To minimize condensation, the heated humidified gas is delivered via heated tubings through a wide‐bore nasal prong. Air flow will be 50 L/min and FiO2 will be titrated to maintain SpO2 above 88%. The comparator will be oxygen delivered via nasal cannula titrated to the same SpO2. Bot CONDITION: Exercise tolerance in patients with interstitial lung diseases ; Respiratory PRIMARY OUTCOME: Exercise capacity assessed as endurance time (Tlim) during a constant work rate cycle test at 75% of the maximal work load (obtained beforehand from a CPET) at a single time point SECONDARY OUTCOME: ; 1. SpO2 measured using a pulse oximeter throughout the CPET performed the first day and during the 2 CWRET performed during the second day; 2. Heart rate (bpm) measured using a pulse oximeter throughout the CPET performed the first day and during the 2 CWRET performed during the second day; 3. Dyspnoea and leg fatigue measured using the Borg scale at before and after of each test; INCLUSION CRITERIA: 1. Fibrosing lung disease on HRCT obtained from medical records, defined as reticular abnormality with traction bronchiectasis with or without honeycombing, with disease extent of >10%, performed within 24 months of screening visit Clinical stability concerning pulmonary infections or acute exacerbations within the previous four weeks of inclusion in the study 2. Absence of recent Myocardial Infarction (within last 3 months), unstable angina, other significant cardiac problems, systolic blood pressure >180 mmHg, diastolic blood pressure >100 mmHg or tachycardia (higher than 100 bpm) 3. Absence of significant orthopaedic, neurological, cognitive and/or psychiatric impairment restricting mobility 4. Not following any exercise programme in the last 3 months 5. Participants between 18 and 80 years old will be recruited and with the ability to give informed consent