Pulmonary Disease, Chronic Obstructive
Conditions
Keywords
COPD, noninvasive ventilation, exercise, CO2 rebreathing
Brief summary
The purpose of this study was to evaluate whether CO2 rebreathing occurs in healthy subjects or patients with COPD ventilated during exercise assisted by the single-limb circuit with a plateau exhalation valve at a given inspiratory positive airway pressure and a minimal level of expiratory positive airway pressure (EPAP) and whether there is a potential threshold for predicting CO2 rebreathing.
Detailed description
Non-invasive ventilation circuit consists of single-limb tubing for inspiration and expiration, including a plateau exhalation valve. As exhaled gases was vented out the plateau exhalation valve at a constant rate, during exercise, with the increase of exhalation flow, single-limb circuit with a plateau exhalation valve might cause carbon dioxide(CO2) rebreathing. Therefore, our aim in the present study was to evaluate whether CO2 rebreathing occurs in COPD patients ventilated during exercise assisted by the single-limb circuit with a plateau exhalation valve and estimate a potential threshold for predicting CO2 rebreathing.
Interventions
DEVICEBiPAP® Vision® ventilator（Ventilator, Philips Respironics™ BiPAP® Vision® ）
See details from arm descriptions.
Sponsors
Guangzhou Institute of Respiratory Disease
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to 80 Years
Healthy volunteers
Yes
Inclusion criteria
* presented clinically stable (no exacerbation in the 4 weeks prior to study participation or with no change in medications); * physician diagnosed COPD, forced expiratory volume in 1s (FEV1) \< 50% predicted; * dyspnea as a main symptom that limited daily activities.
Exclusion criteria
* subjects with obvious pulmonary bullae demonstrated by chest CT scan or X-ray; * examination or facial trauma/malformation, recent facial, upper airway or upper gastrointestinal tract surgery, that would preclude receiving NIV therapy; * a history of coronary artery disease or cardiac arrhythmias or potential electrocardiographic alterations; * a history of uncontrolled hypertension, or other respiratory diseases; * oxygen saturation(SpO2) \< 88% at rest with a fraction of inspired oxygen (FiO2) ≥ 0.5; * patients with musculoskeletal or neurological disorders; * or failure to comply with the research protocol.
Design outcomes
Primary
| Measure | Time frame |
|---|---|
| mean exhalation valve flow | Measurements were collected continuously throughout a symptom-limited cycle exercise test （test lasts for about 8-12 min） while subjects breathed through the full face mask. Analyses were made breath by breath during the whole test process. |
Secondary
| Measure | Time frame |
|---|---|
| mean inspiratory fraction of CO2 for each tidal volume | Measurements were collected continuously throughout a symptom-limited cycle exercise test （test lasts for about 8-12 min） while subjects breathed through the full face mask. Analyses were made breath by breath during the whole test process. |
| fraction of end-tidal carbon dioxide partial pressure | Measurements were collected continuously throughout a symptom-limited cycle exercise test （test lasts for about 8-12 min） while subjects breathed through the full face mask. Analyses were made breath by breath during the whole test process. |
| inspiratory time | Measurements were collected continuously throughout a symptom-limited cycle exercise test （test lasts for about 8-12 min） while subjects breathed through the full face mask. Analyses were made breath by breath during the whole test process. |
| mean exhalation flow | Measurements were collected continuously throughout a symptom-limited cycle exercise test （test lasts for about 8-12 min） while subjects breathed through the full face mask. Analyses were made breath by breath during the whole test process. |
| respiratory rate | Measurements were collected continuously throughout a symptom-limited cycle exercise test （test lasts for about 8-12 min） while subjects breathed through the full face mask. Analyses were made breath by breath during the whole test process. |
| inspiratory tidal volume | Measurements were collected continuously throughout a symptom-limited cycle exercise test （test lasts for about 8-12 min） while subjects breathed through the full face mask. Analyses were made breath by breath during the whole test process. |
| expiratory tidal volume | Measurements were collected continuously throughout a symptom-limited cycle exercise test （test lasts for about 8-12 min） while subjects breathed through the full face mask. Analyses were made breath by breath during the whole test process. |
| expiratory time | Measurements were collected continuously throughout a symptom-limited cycle exercise test （test lasts for about 8-12 min） while subjects breathed through the full face mask. Analyses were made breath by breath during the whole test process. |
Countries
China
Outcome results
None listed