Effect of ipratropium bromide aerosol on respiratory function in patients under ventilator treatment.

Twenty patients, 36-78 years old, with a history of chronic obstructive lung disease, and immediately after operation mostly for cardiac disease, were treated with ipratropium bromide (IB, 15 cases) or placebo (5 cases). A metered dose inhaler with a new adapter was used during postoperative ventilator treatment. In the IB group the heart rate did not change, but the inspiratory resistance decreased and the arterial oxygen tension increased. This is considered to indicate an effect not only on large but also on small airways, or an improvement of the ventilation/perfusion relationship. The investigation also demonstrated the practical usefulness of the new adapter.