Non-invasive Mechanical Ventilation as a Rescue Therapy to Relieve Dyspnea in Patients With Stable Severe COPD

Study Overview
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Brief Summary
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The purpose of this study is to determine whether non-invasive mechanical ventilation(NIV), playing the role as a rescue therapy , are effective in relieving exertional dyspnea in stable severe COPD patients.

Detailed Description
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Chronic obstructive pulmonary disease(COPD) is a preventable and treatable illness, which is clinically characterized by persistent airflow limitation that is usually progressive. It's well known that airflow limitation lead to air trapping particularly during exercise, resulting in increased dyspnea and limitation of exercise capacity. Thus, COPD patients often unconsciously adopt a sedentary lifestyle, probably due to distressing exertional dyspnea. The sedentarism results in physical deconditioning and alterations of the peripheral muscles, and the latter one causes more exertional dyspnea and fatigue, which in turn leads to much more sedentarism, forming the vicious cycle of sedentarism, dyspnea/fatigue and more sedentarism. Thereby, measures should be taken to interrupt this vicious cycle. Some previous studies suggested that niv acting as an add-on therapy could help unloading the inspiratory muscle, reducing the dynamic compression of the airway, diminishing the dynamic hyperinflation,to some extent, relieved dyspnea during exercise in COPD patients. However,those measures were taken during exercise, acting as an add-on therapy. Whether NIV can play a role as a rescue therapy to relieve exertional dyspnea while the patients are already undergoing optimal treatment with bronchodilator and anti-inflammatory medication is still not quite clear. Therefore, we hypothesize that niv as a rescue-therapy has the same effect on relieving dyspnea in stable severe COPD patients just like the add-on therapy.

Official Title
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The Efficacy of Non-invasive Mechanical Ventilation as a Rescue Therapy for Relieving Dyspnea in Patients With Stable Severe COPD

Conditions
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Chronic Obstructive Pulmonary Disease

Intervention / Treatment
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* Device: niv plus oxygen therapy
* Device: oxygen therapy


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: severe COPD (post bronchodilator FEV1/FVC < 70% and FEV1 < 50% predicted) stable clinical condition(no exacerbation in the 4 weeks prior to study participation with no change in medications) dyspnea as a main symptom that limited daily activities Exclusion Criteria: obvious pulmonary bullae demonstrated by chest CT scan or X-ray examination facial trauma/malformation; recent facial, upper airway or upper gastrointestinal tract surgery oxygen saturation(SpO2) < 88% at rest with a fraction of inspired oxygen(FiO2) ≥ 0.5 systolic blood pressure > 160mmHg or diastolic blood pressure > 100mmHg at rest unstable angina or a myocardial infarct in the previous four weeks resting sinus tachycardia ( > 120 beats/min) patients with musculoskeletal or neurological disorders patients who are unable to give informed consent

Ages Eligible for Study
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Minimum Age: 30 Years
Maximum Age: 80 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: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: niv plus oxygen therapy<br>oxygen therapy is given during the whole experimental process, niv is given at peak exercise until the borg scale reaches it's baseline point | Device: niv plus oxygen therapy<br>* NIV given on Philips Respironics BiPAP Vision apparatus.<br>* Other names: Philips Respironics BiPAP Vision;|
| Active Comparator: oxygen therapy<br>oxygen therapy is given during the whole experimental process | Device: oxygen therapy<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Borg scale |  | baseline,repeated measurement for about ten minutes after intervention | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Inspiratory capacity(IC) |  | baseline,repeated measurement for about ten minutes after intervention | 
| surface electromyography(sEMG) |  | baseline,repeated measurement for about ten minutes after intervention | 
| respiratory parameters | minute ventilation(VE); tidal volume(Vt); respiratory rate(RR); inspiratory time(Ti); total duty cycle(Ttot) | baseline,repeated measurement for about ten minutes after intervention | 
| oxygen saturation(SpO2) |  | baseline,repeated measurement for about ten minutes after intervention | 
| Heart Rate(HR) |  | baseline,repeated measurement for about ten minutes after intervention | 
| the total recovery time |  | repeated measurement for about ten minutes after intervention | 
| mouth pressure(Pmo) |  | baseline,repeated measurement for about ten minutes after intervention | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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COPD, dyspnea, exercise, Noninvasive Ventilation