Pulmonary gas exchange effects by nitroglycerin,dopamine and dobutamine during one-lung ventilation in man

The effects of nitroglycerin, dopamine and dobutamine on pulmonary gas exchange were determined in 21 adult patients during two-lung and one-lung ventilation. Nitroglycerin, in I μg·kg^?1·min^?1, decreased cardiac index (CI) andPaO₂ during both two-and one-lung ventilation, and increased in Qs/Qt during one-lung ventilation. There were no significant changes in the measured variables during infusion of dopamine, 5 μg·kg^?1·min^?1. Dobutamine, 5μg·kg^?1·min^?1, increased Cl and PaO₂ did not change during two-lung ventilation. During one-lung ventilation, PaO₂ increased from (mean value ±SD) 168 ± 46 to 201 ± 52 mmHg (P < 0.01) with dobutamine infusion. Qs/Qt decreased from 29.2 ± 7.0 to 26.0 ± 6.2 per cent (P < 0.05) without any change in pulmonary vascular resistance index during one-lung ventilation. We conclude that dobutamine has advantages over dopamine and nitroglycerin during one-lung ventilation.