Clinical trial NCT02285400: Effects of CPAP Level on Respiratory Mechanics and Central Drive in Patients With COPD
Official title: Effects of Continuous Positive Airway Pressure (CPAP) Level on Respiratory Mechanics and Central Drive in Patients With Chronic Obstructive Pulmonary Disease
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Chronic Obstructive Pulmonary Disease (COPD)
Keywords: COPD
CPAP
Central Drive
Lead sponsor: Zhujiang Hospital
Sponsor class: OTHER
Collaborators: name: Guangzhou Institute of Respiratory Disease
First posted: 2014-11-07
Enrollment: 30
Sex: ALL
Minimum age (years): 40
Maximum age (years): 70
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NON_RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: Chronic Obstructive Pulmonary Disease (COPD) is a common respiratory disease characterized by airflow limitation that is progressive and not fully reversible. Expiratory flow limitation (EFL) is the main mechanism leading to dynamic pulmonary hyperinflation (DPH) and intrinsic positive end-expiratory pressure (PEEPi). DPH and PEEPi lead to increased inspiratory muscle efforts and impaired central drive mechanical and ventilation coupling, which is an important mechanism of dyspnea. Appropriate setting of extrinsic PEEP (PEEPe) can decrease inspiratory efforts and work of breathing, improve patient-ventilator synchrony in severe COPD patients with PEEPi and treated with mechanical ventilation. Nevertheless, the effects of CPAP/PEEPe level on respiratory mechanics, especially on central drive mechanical and ventilation coupling, still need further investigations.

In the present study, about 40 patients with COPD will be recruited as research subjects. And the investigators aim to observe the changes in respiratory mechanics, central drive mechanics, central drive mechanical and ventilation coupling at different levels of CPAP. Contrast analysis will be conducted to evaluate the effects of CPAP level on respiratory mechanics and central drive during DPH, which may provide a reasonable basis for the clinical application of CPAP to COPD patients and the exploration of a new reasonable CPAP setting method.

Detailed description: Patients with COPD are divided into two groups: moderate group and severe group, both of which are intervented by CPAP level. The static pressure volume curves of the lung and chest wall (Campbell diagram) were established with slow deep respiratory manoeuvre. Before using CPAP level, we will measure the relevant parameters of lung volume, respiratory flow, diaphragm electromyogram, central drive mechanical and ventilation coupling. Then incremental CPAP level will be applied to investigate the effects of CPAP level on the above mentioned respiratory mechanics parameters.

Eligibility criteria: Inclusion Criteria:

* Patients from Zhu jiang Hospital,Southern Medical University
* Patients aged 40-70 years old
* Patients with pulmonary function test of forced expiratory volume at one second (FEV1)/forced vital capacity(FVC) \< 70% and 30% ≤ FEV1%pred \< 80%
* Patients in a clinically stable state
* Patients who signed informed consent.

Exclusion Criteria:

* Patients with signs of an airway infection
* Patients with an acute exacerbation during the previous 4 weeks
* Patients with giant bulla(≥3cm in diameter)
* Patients with recent upper abdominal surgery
* Patients with one or more of the following diseases: esophageal cancer, reflux esophagitis, severe obstructive sleep apnea (apnea hypopnea index\>15/hr), neuromuscular disease, or significant heart failure
* Patients with poor compliance.

Primary outcomes:
measure: Diaphragmatic function
timeFrame: Change from baseline in diaphragm electromyogram at 12 cmH2O CPAP level. (10 minutes later,20minutes later,30 minutes later, 40 minutes later)
Secondary outcomes:
measure: Respiratory pressure
timeFrame: Chang from baseline in respiratory pressure at 12 cmH2O CPAP level.(10 minutes later,20minutes later,30 minutes later, 40 minutes later)
measure: Respiratory volume
timeFrame: Chang from baseline in respiratory volume at 12 cmH2O CPAP level. (10 minutes later,20minutes later,30 minutes later, 40 minutes later)
measure: Degree of dyspnea
timeFrame: Chang from baseline in dyspnea at 12 cmH2O CPAP level. (10 minutes later,20minutes later,30 minutes later, 40 minutes later)
Other outcomes:
measure: Pulse oxygen saturation (SpO2)
timeFrame: Chang from baseline in SpO2 at 12 cmH2O CPAP level. (10 minutes later,20minutes later,30 minutes later, 40 minutes later)
measure: End tidal carbon dioxide pressure (PETCO2)
timeFrame: Chang from baseline in PETCO2 at 12 cmH2O CPAP level. (10 minutes later,20minutes later,30 minutes later, 40 minutes later)
Locations:
city: Guangzhou
country: China
facility: Zhujiang Hospital,Southern Medical Universtiy
state: Guangdong
Study officials:
affiliation: Zhujiang Hospital,Southern Medical Unversity
name: Xin Chen, Doctor
role: PRINCIPAL_INVESTIGATOR
References: