Effect of isoproterenol on gas exchange during air and oxygen breathing in patients with chronic pulmonary diseases.

Abstract

The effect of isoproterenol on gas exchange during breathing of air and of 100 per cent oxygen was investigated in 40 patients with chronic lung disease (17 with emphysema, 7 with sarcoidosis, 10 with idiopathic fibrosis, and 6 with pneumonectomy). The results were compared with those of studies performed in 25 patients with asthma and 14 normal subjects. In nonasthmatic patients as well as in normal subjects, after administration of isoproterenol no significant change in arterial oxygen tension occurred during the breathing of air or 100 per cent oxygen. In contrast, in the patients with asthma, arterial oxygen tension decreased 8 mm Hg during breathing of air, and increased 30 mm Hg during breathing of 100 per cent oxygen. A significant improvement in forced expiratory flow was seen only in patients with asthma. Pulmonary diffusing capacity and pulmonary capillary blood volume decreased in patients with asthma after administration of isoproterenol but showed no significant change in the normal subjects ...