Ventilation-drive Coupling to Evaluate The Efficacy of Inhaled Bronchodilators in Patients With COPD
Ventilation-drive Coupling to Evaluate The Efficacy of Inhaled Bronchodilators in Patients With COPD
Chronic Obstructive Pulmonary Disease (COPD) is a major cause of chronic morbidity, mortality
 and disability throughout the world, leading to a heavy social and economic
 burden.Bronchodilators, the most commonly used drugs in COPD patients, have been shown to
 reduce dyspnea, improve exercise tolerance and improve health status. However,conventional
 lung function parameters such as forced vital capacity (FVC) and forced expiratory volume in
 one second (FEV1) frequently fail to detect significant functional responses to
 bronchodilators in patients with chronic airflow obstruction. It is necessary for clinical
 and scientific reasons to develop a new tool to objectively assess the effect of different
 treatments including bronchodilator on COPD. Our previous study showed that Ventilation-drive
 coupling may be more sensitive and accurate to evaluate the efficacy of inhaled
 bronchodilators in patients with COPD because it could better reflect the pathological and
 physiological characteristics of COPD.

 Based on the above conclusion, the present study were performed using the experimental
 methods of placebo and self-controlled. We aimd to explore the value of ventilation-drive
 coupling in evaluating the efficacy of bronchodilators on COPD and provide a reasonable basis
 for the clinical application of this index.
Patients were randomly assigned to one of two intervention groups:

 1. Group A: Patients inhaled placebo, ipratropium 80μg, salbutamol 400 μg in sequence;

 2. Group B: Patients inhaled placebo, salbutamol 400μg, ipratropium 80 μg in sequence.

 The data were collected in 30 minutes after patients inhaled placebo,in 30 minutes after
 ipratropium and in 15 minutes after salbutamol.
Inclusion Criteria:

 Patients aged 40-70 years old; Patients with pulmonary function test of FEV1/FVC < 70% and
 FEV1%pred < 50%; 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.