Acute hemodynamic effects of inhaled nitric oxide, dobutamine and a combination of the two in patients with mild to moderate secondary pulmonary hypertension

Introduction. The use of low-dose dobutamine to maintain hemodynamic stability in pulmonary hypertension may have a detrimental effect on gas exchange. The aim of this study was to investigate whether inhaled nitric oxide (INO), dobutamine and a combination of the two have beneficial effects in patients with end-stage airway lung disease and pulmonary hypertension. Method. Hemodynamic evaluation was assessed 10 min after the administration of each drug and of their combination, in 28 candidates for lung transplantation. Results. Administration of INO caused a reduction in mean pulmonary arterial pressure (MPAP), an increase in PaO₂ with a significant reduction in venous admixture effect (Q_s/Q_t). Dobutamine administration caused an increase in cardiac index and MPAP, with a decrease in PaO₂ as a result of a higher Q_s/Q_t. Administration of a combination of the two drugs caused an increase in the cardiac index without MPAP modification and an increase in PaO₂ and Q_s/Q_t. Conclusion. Dobutamine and INO have complementary effects on pulmonary circulation. Their association may be beneficial in the treatment of patients with mild to moderate pulmonary hypertension.