Effects of inhaled bronchodilators on pulmonary hemodynamics at rest and during exercise in patients with COPD

Introduction: Inhaled anticholinergic drugs are often recommended for use a s a first-line therapy for patients with COPD because they provide similar or more effective bronchodilating actions, as well as fewer side effects. I t is not known, however, which class of bronchodilators is more advantageou s for pulmonary hemodynamics, particularly during exercise. Objectives: To compare the effects of oxitropium and fenoterol on pulmonary hemodynamics in patients with COPD at rest and during exercise. Patients: The study participants consisted of 20 consecutive male patients with stable COPD, a mean (+/- SD) age of 68 +/- 8 years old, and an FEV1/FV C ratio of 47.5 +/- 10.%, Methods: Eleven patients inhaled two puffs of oxi tropium, and nine patients inhaled two puffs of fenoterol, Seven members of each group performed incremental exercise using a cycle ergometer, The hem odynamic measurements with right heart catheterization were performed by ta king the average of three consecutive respiratory cycles before and after t he administration of inhaled bronchodilators at rest and during exercise. Results: At rest, despite a similar improvement of spirometric data with th e two drugs, fenoterol, not oxtropium, caused significant increases in hear t rate and cardiac output, a decrease in pulmonary vascular resistance, and a deteriorated Pao(2). During exercise, however, both drugs similarly atte nuated elevations in the mean pulmonary arterial pressure (40 +/-2 to 38 +/ - mm Hg by oxitropium, and 41 +/- to 36 +/- mm Ng by fenoterol), the mean p ulmonary capillary wedge pressure, and the mean right atrial pressure. Conclusion: Our findings indicate that both classes of bronchodilators are equally beneficial in the attenuation of right heart afterload during exerc ise in patients with COPD.