The aim of this multicenter crossover trial is to describe the effect of adding a therapeutic dose of exertional oxygen therapy, in terms of exercise performance, gas exchange, heart rate, symptoms perception and subjective easiness of performance, in a cohort of subjects hospitalized in specialized pulmonary rehabilitation centers with a diagnosis of chronic respiratory failure and/or exertional hypoxemia due to chronic obstructive pulmonary disease or interstitial lung disease.
Researchers will compare the walking performance during 6-minute walk test performed with the liters of oxygen administered as prescribed at rest (for patients with chronic respiratory failure) or in room air (for patients with exertional hypoxemia only), to the performance during a 6-minute walk test performed with the double the flow rate prescribed at rest, or with 2 L/min for patients with exertional hypoxemia only. The two tests will be performed in random order, at least 3 hours apart and no later than 24 hours apart from each other.
The main outcome will be the difference between the distance walked in the two 6-minute walk test in the two conditions. Furthermore, will be also collected and compared: the oxygen saturation and heart rate every minute, the initial and final dyspnea and fatigue, as assessed by Borg scale, and the easiness of performance through a dedicated questionnaire. The estimated sample size will be 114 patients.
This study will provide some basis for a more accurate prescription of exercise-related oxygen therapy, offering insights into the phenotype of patients who may derive the greatest benefit from this intervention. It will also stimulate discussion regarding the optimal timing and dosing of oxygen administration during exertion in patients with respiratory failure.
Adults aged 18 years or older
Diagnosis of chronic respiratory disease admitted for pulmonary rehabilitation
Chronic obstructive pulmonary disease with exertional hypoxemia
Chronic obstructive pulmonary disease with chronic respiratory failure requiring long-term oxygen therapy
Lung diseases other than chronic obstructive pulmonary disease or interstitial lung disease
Resting oxygen flow requirement greater than 4 liters per minute
Orthopedic, neurological, or cognitive conditions that may limit walking performance
Recent cardiovascular or cerebrovascular events within the previous 3 months
Crossover
Usual Oxygen During 6-Minute Walk Test
Other interventionParticipants perform the 6-minute walk test using the oxygen flow prescribed at rest for chronic respiratory failure, or room air for participants with exertional hypoxemia only. Oxygen is delivered through nasal cannula using standard equipment. Walking distance, oxygen saturation, heart rate, and symptoms are recorded during the test.
Supplemental Oxygen During 6-Minute Walk Test
Other interventionParticipants perform the 6-minute walk test using supplemental oxygen during exercise. Oxygen flow is set at double the resting prescription for participants with chronic respiratory failure, or at two liters per minute for participants with exertional hypoxemia. Oxygen is delivered through nasal cannula using standard equipment. Walking distance, oxygen saturation, heart rate, and symptoms are recorded during the test.
Change in 6-Minute Walk Distance With Supplemental Oxygen
This outcome measures the difference in walking distance during the 6-minute walk test when participants use supplemental oxygen (O2PLUS) compared to their usual oxygen setting or room air (O2REST). The change is calculated as the distance walked with supplemental oxygen minus the distance walked with usual oxygen or room air. This outcome reflects the short-term effect of supplemental oxygen on exercise performance.
Oxygen Saturation During the 6-Minute Walk Test
This outcome measures oxygen saturation levels recorded during the 6-minute walk test when participants walk with supplemental oxygen and when they walk with their usual oxygen setting or room air. Oxygen saturation is recorded every minute during the test to evaluate changes in blood oxygen levels during walking.
Heart Rate During the 6-Minute Walk Test
This outcome measures heart rate recorded during the 6-minute walk test under both oxygen conditions. Heart rate is monitored every minute during walking to assess the cardiovascular response to exercise with and without supplemental oxygen.
Dyspnea Before and After the 6-Minute Walk Test
This outcome measures the level of dyspnea reported by participants using the Borg Dyspnea Scale before the test, immediately after the test, and three minutes after recovery. Results are compared between walking with supplemental oxygen and walking with usual oxygen or room air.
Muscles Fatigue Before and After the 6-Minute Walk Test
This outcome measures perceived fatigue using the Borg Fatigue Scale before the test, immediately after the test, and three minutes after recovery. Fatigue scores are compared between the two oxygen conditions.
Participant-Reported Perception of Walking Performance
This outcome measures participants' subjective perception of their walking performance after completing both 6-minute walk tests. Participants rate perceived differences in shortness of breath, fatigue, and overall ability to walk between the two tests using a structured dedicated questionnaire.
Click on the lead sponsor to view all of their trials.
