Bronchodilator therapy in COPD: physiological effects

Bronchodilator therapy is the first step in improving dyspnoea and exercise endurance in patients with COPD. Recent studies have challenged the long-held view that airway obstruction in COPD is irreversible. We now know that even in the setting of minor or no change in traditional spirometry, bronchodilator therapy is associated with consistent, and often impressive, reduction in lung hyperinflation. This pharmacological lung volume reduction is linked to improved inspiratory muscle function and enhanced neuromechanical coupling of the respiratory system during activity, even in those with advanced disease. Moreover, these improvements in dynamic mechanics provide a sound physiological rationale for observed bronchodilator-induced improvements in the important patient-centred outcomes of reduced dyspnoea and activity limitation. This article has been adapted from an ERS Research Seminar held in Como, Italy in 2007. The original slides and other material can be found at www.ers-education.org