Evaluation of the Reversibility of the Bronchial Obstruction by Impulse Oscillometry Technique in Chronic Obstructive Pulmonary Disease (COPD): Correlation With Functional Features Measured by Plethysmography and Dyspnoea

Limitation of expiratory flows is considered as the main determiner of dynamic distension and dyspnoea in chronic obstructive pulmonary disease (COPD). The analysis of proximal and distal resistances should allow to better appreciate the functional impact.

This study should also allow to specify the best parameters in respiratory functional explorations useful for the follow-up in COPD and to specify the relevance of functional indications other than the forced expiration volume at 1 second (FEV1) or the functional residual capacity (FRC) to estimate in a more relevant way the clinical improve with the increase of the therapeutic load (increase of posology, association of two bronchodilatators, addition of an anti-inflammatory drug, thus etc…) at already handled patients suffering from a persistent dyspnoea insufficiently relieved.

Inclusion Criteria:

• COPD with dyspnoea with Medical Research Council scale (MRC) >1,
• No exacerbation for 6 weeks
• No bronchodilatator short action(share) (ß 2 agonist or ipratropium) within 6 hours before the respiratory evaluation and the test of reversibility.
• Patient under current treatment (ß2 long-acting agonist (LABA) or anticholinergic long-acting (LLAMA(LAMA)) or LABA-corticoid association inhaled (CSI), or triples LABA-CSI-LAMA association) stable for at least 4 weeks, and taken for at least the 1 hour the day of the visit
• Having given a written consent

Exclusion Criteria:

• Patient Under 18
• Other respiratory illness
• Clinically significant left cardiac failure
• Obesity with BMI > 35 kg / m2)
• Unable to perform respiratory evaluations
• Contraindication to the salbutamol or to the ipratropium bromide or to one of its components
• Pregnant or breast-feeding woman
• Unable to agree
• No social security scheme