Abstract

Terbutaline sulphate was given intravenously to 10 patients with pulmonary vascular disease secondary to chronic hypoxia. The resting cardiac index increased after terbutaline in all the patients between 5 and 74% above the control level. The greatest change was seen in patients who had received the largest total dose. The rise in cardiac index was associated with a fall in pulmonary vascular resistance although mean pulmonary artery pressure remained unaltered. There was a significant increase in the venous admixture but this did not adversely affect the arterial oxygen tension. The peak expiratory flow rate did not change significantly but there was an increase in ventilation from a mean value of 4.36 1/min/m2 to 4.67 1/min/m2. The results show that terbutaline has little adverse effect on the pulmonary circulation or gas exchange in patients with irreversible airways disease who are in a stable state.