[Effects of denopamine on hemodynamics and blood gases in secondary pulmonary hypertension].

The acute hemodynamic and blood gas changes caused by denopamine (2 micrograms/kg/min, d.i.) were investigated in 13 patients with chronic respiratory failure and secondary pulmonary hypertension. Denopamine significantly reduced mean pulmonary arterial pressure from 25 +/- 7 to 23 +/- 7 mmHg (p less than 0.05), and pulmonary vascular resistance from 314 +/- 166 to 276 +/- 168 dyne/sec/cm-5 (p less than 0.05), while mean systemic arterial pressure and systemic vascular resistance showed no significant change. Pulmonary-systemic vascular resistance ratio was reduced significantly from 0.22 +/- 0.09 to 0.18 +/- 0.09 (p less than 0.05). These findings suggest that denopamine has more marked effects on the pulmonary artery than on systemic arteries. Arterial oxygen tension (PaO2) increased significantly from 59.0 +/- 8.1 to 62.5 +/- 10.5 Torr (p less than 0.01), and arterial carbon dioxide tension (PaCO2) decreased significantly from 49.1 +/- 6.8 to 44.6 +/- 7.0 Torr (p less than 0.01) by denopamine. Mixed venous oxygen tension (PvO2), which is an indicator of tissue oxygenation, increased significantly from 33.3 +/- 3.5 to 34.4 +/- 3.3 Torr (p less than 0.05). We conclude that denopamine is thought to be useful for the improvement of hemodynamics and tissue oxygenation in patients with secondary pulmonary hypertension. However, further long-term studies are necessary to establish its therapeutic efficacy.