Hyperoxia During Pulmonary Rehabilitation in Chronic Lung Disease - Does it Matter?

Study Overview
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Brief Summary
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Chronic respiratory diseases are a global burden. Treatment options have improved in recent years, pulmonary rehabilitation plays a key role. Oxygen therapy is recommended in patients with a low saturation at rest, but no clear guidance is given for patients who desaturate during exercise. The effect of ambulatory oxygen during exercise is not yet completely understood, especially in those patients with exercise-induced desaturation. Aim: The goal of this study is to analyse the effect of supplemental oxygen given during a constant work rate exercise test (CWRET) on a cycle ergometer compared to sham air. Methods: We plan to include 25 Patients respiratory patients undergoing pulmonary rehabilitation (male and female; aged >18 years; stable condition >3 weeks (e.g. no exacerbations); resting oxygen saturation (SpO2) ≥ 88%) with exercise induced hypoxemia defined by a fall in oxygen saturation by ≥ 4% during a 6-minute walking test. Patients will undergo an incremental exercise test with a ramp protocol (for evaluating the maximal workload) and two CWRET (75% of the maximal workload) with ambulatory oxygen or placebo (sham air) via standard nasal canula at a flow rate of 5l/min. Patients and assessors will be blinded. The difference endurance time of the CWRET with oxygen vs. sham air will be the primary outcome of this study. Data will be summarized by means (SD) and medians (quartiles) for normal and non-normal distributions. Effects of treatment will be evaluated by mean differences with 95% confidence intervals, T-tests or Wilcoxon matched pair tests as appropriate. A p-value threshold of <0.05 or a confidence interval not including zero will be considered as statistically significant. Analyses will be performed according to the intention to treat principle.

Official Title
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Hyperoxia During Pulmonary Rehabilitation in Chronic Lung Disease - Does it Matter?

Conditions
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Chronic Obstructive Pulmonary Disease, Asthma, Pulmonary Hypertension, Interstitial Lung Disease, Chronic Lung Disease

Intervention / Treatment
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* Other: Oxygen


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: We will include male and female lung disease patients undergoing pulmonary rehabilitation: aged ≥ 18 years; stable condition > 3 weeks (e.g. no exacerbations); resting oxygen saturation (SpO2) ≥ 88% and exercise induced hypoxemia defined by a fall in SpO2 by ≥ 4% during a 6-minute walking test (6MWT); informed consent as documented by signature. Exclusion Criteria: Severe daytime resting hypoxemia (SpO2 < 88% or partial pressure of oxygen (PaO2) < 8 kPa); unstable condition requiring adaptation of pharmacologic and other treatment modalities or requirement of intensive care or relevant severe concomitant disease; inability to follow the procedures of the study, e.g. due to language problems, psychological disorders, neurological or orthopedic problems with walking disability or inability to ride a bicycle; women who are pregnant or breast feeding; enrolment in another clinical trial with active treatment.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Placebo Group<br>Start with Constant Work Rate Exercise Test with 5l/min room air applied via nasal cannula. | Other: Oxygen<br>* Standard supplemental Oxygen therapy (5l/min) will be applied with an oxygen concentrator via nasal cannula.<br>|
| Experimental: Experimental Group<br>Start with Constant Work Rate Exercise Test with 5l/min Oxygen Therapy applied via nasal cannula. | Other: Oxygen<br>* Standard supplemental Oxygen therapy (5l/min) will be applied with an oxygen concentrator via nasal cannula.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Constant Work Rate Exercise Test | Endurance time measured with Constant Work Rate Exercise Test (CWRET) (75% of the maximal work rate from the maximal ramp exercise test) | 7 days | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| SpO2 | SpO2 by finger pulse oximetry, brain and muscle tissue oxygenation by near infrared spectroscopy (NIRS) at rest and end-exercise CWRET | 7 days | 
| Heart Rate | Heart rate at rest and end-exercise CWRET | 7 days | 
| Borg Scale (0-10) | Borg scale (dyspnoea and fatigue) at rest and end-exercise CWRET | 7 days | 
| Blood Pressure | Blood pressure at rest and end-exercise CWRET | 7 days |