Effects of Non-invasive Ventilation on Respiratory Mechanics and NRD in Patients With Stable COPD

Effects of Non-invasive Positive Pressure Ventilation at Different Pressure on Respiratory Mechanics and Neural Respiratory Drive(NRD)in Patients With Stable Chronic Obstructive Pulmonary Disease(COPD)

Chronic obstructive pulmonary disease (COPD) is a chronic respiratory disease characterized by persistent respiratory symptoms and airflow limitation. Pervasive dynamic pulmonary hyperinflation (DPH) and intrinsic positive end-expiratory pressure (PEEPi) can increase inspiratory threshold load and respiratory effort, leading to abnormal changes in respiratory mechanics and neural respiratory drive (NRD). Non-invasive positive pressure ventilation (NPPV) is not only widely used in respiratory failure, but also is one of the important lung rehabilitation strategies. Several studies have reported that the use of biphasic positive airway pressure (BIPAP) mode for NPPV can improve ventilation, reduce NRD, improve NRD coupling, significantly reduce inspiratory muscle load and relieve symptoms. However, relatively few studies are reported that the NPPV is used in COPD patients without non-respiratory failure. Therefore, we suppose that for stable COPD patients without respiratory failure, early intervention with NPPV may reduce DPH, eliminate the adverse effects of PEEPi, reduce the respiratory muscle load, improve the respiratory physiological characteristics, and delay the progression of the disease. Therefore, the purpose of this study is to observe the influence of different levels of BIPAP ventilation on respiratory mechanics and NRD in patients with stable COPD, and to explore whether BiPAP ventilation can be used as a pulmonary rehabilitation method for early intervention of COPD and provide a theoretical basis for subsequent clinical trials.

The patients with COPD will be admitted in one intervention groups. Before using BiPAP ventilation, we will measure the relevant parameters of lung volume, respiratory flow, diaphragm electromyogram, neural respiratory drive mechanical and other baseline index. Then incremental pressure support will be applied to investigate the effects of different levels of BIPAP ventilation on respiratory mechanics and neural respiratory drive.

Inclusion Criteria:

• Patients with pulmonary function test of forced expiratory volume at one second (FEV1)/forced vital capacity(FVC) < 70% after inhalation of bronchial dilation agent. Patients in a clinically stable state.

Exclusion Criteria:

• Patients they had other respiratory diseases, or evidence of pneumothorax or mediastinal emphysema and pacemaker installed. Patients with acute cardiovascular event and severe cor pulmonale. Patients with poor compliance. An Other causes of diaphragmatic dysfunction.