LAMA improves tissue oxygenation more than LABA in patients with COPD.

The effect of bronchodilators is mainly assessed with forced expiratory volume in 1 s (FEV) in chronic obstructive pulmonary disease (COPD). Their impact on oxygenation and lung periphery is less known. Our objective was to compare the action of long-acting β-agonists (LABA-olodaterol) and muscarinic antagonists (LAMA-tiotropium) on tissue oxygenation in COPD, considering their impact on proximal and peripheral ventilation as well as lung perfusion.