Negative Pressure Ventilator in Long-term Pulmonary Rehabilitation for Chronic Obstructive Pulmonary Disease

Study Overview
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Brief Summary
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Chronic obstructive pulmonary disease (COPD) is characterized by irreversible airflow obstruction with chronic airway inflammation and emphysematous changes in the lung parenchyma, thus leading to air-trapping, as well as extional dyspnea. The investigators have previously observed that NPV used as an adjuvant to pulmonary rehabilitation improves lung function, exercise capacity, and reduces exacerbations. The investigators now sought to determine whether long-term maintenance NPV improves long-term clinical outcomes and reduces mortality in COPD.

Detailed Description
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Chronic obstructive pulmonary disease (COPD) is characterized by irreversible airflow obstruction with chronic airway inflammation and emphysematous changes in the lung parenchyma, thus leading to air-trapping, as well as extional dyspnea. The mechanism underlying desaturation during 6MWT in patients with COPD is multifactorial involving dynamic hyperinflation and impaired gas exchange that worsens ventilation-perfusion mismatch. Previous studies have shown that oxygen desaturation during the 6MWT predicts mortality and increases the risk of adverse outcomes in COPD patients. However, there is a paucity of studies that have looked at effective treatments to counter the consequences of hypoxemia during exertion. The investigators have established a hospital-based maintenance pulmonary rehabilitation program together with NPV for COPD, and the investigators have shown that the benefits of NPV improves lung function and exercise capacity, and reduces acute exacerbation and medical costs. The investigators now sought to determine whether long-term maintenance NPV improves long-term clinical outcomes and reduces mortality in COPD.

Official Title
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Negative Pressure Ventilator in Long-term Pulmonary Rehabilitation for Chronic Obstructive Pulmonary Disease: Outcome Analysis

Conditions
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Pulmonary Disease, Chronic Obstructive

Intervention / Treatment
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* Device: maintenance negative pressure ventilation (Philips Respironics Lifecare NEV-100)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Main diagnosis of Chronic Obstructive Pulmonary Disease Stable status at enrollment Able to come to pulmonary rehab center Exclusion Criteria: Infection or acute excerbation condition at enrollment Severe neuromuscular, cardiac disease or dementia Unable to perform six minute walk test

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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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| NPV<br>a hospital-based maintenance NPV program including NPV support, breathing training and an educational program (relaxation techniques, and home pacing walking exercise) in daily clinical practice. Patients received NPV with breathing training via the cuirass ventilator (Philips Respironics Lifecare NEV-100) settings for 60 min. The ventilator was set to control model with frequency of 12 cycles/min, 30% of the ratio of inspiratory time to total breathing cycle time (Ti/Ttot) and delivered negative pressures ranging -20 to -30 cm H2O. In the NPV group, patients underwent the hospital-based NPV once every week as the maintenance program. | Device: maintenance negative pressure ventilation (Philips Respironics Lifecare NEV-100)<br>* hospital-based NPV once every week as the maintenance program<br>|
| Control<br>If patients do not wish to enter the hospital-based NPV program, they are placed in the control group and are trained to perform breathing training, relaxation techniques and home pacing walking exercise. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Overall mortality | Death of all causes | 8 years | 
| COPD-related mortality | pulmonary, lung cancer and cardiovascular death | 8 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Lung function | forced expiratory volume in one second (FEV1) | 8 years | 
| 6 minute walking distance | 6 minute walking test distance | 8 years | 
| Severe exacerbations | ER visits or hospitalisations | 8 years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Chronic obstructive pulmonary disease, Maintenance Negative Pressure Ventilation- assisted pulmonary rehabilitation, Six minute walk test, Overall survival