Hypotension in Preterm Infants with Significant Patent Ductus Arteriosus: Effects of Dopamine

Objective To study the effects of dopamine on systemic arterial pressure (SAP) and systemic blood flow (SBF) (estimated with the superior vena cava [SVC] flow) in preterm infants with hypotension and patent ductus arteriosus (PDA). Study design Clinical and echocardiographic variables were measured before and 2 hours after starting dopamine in premature infants <32 weeks gestational age with PDA and systemic hypotension. Results Seventeen premature infants were included (gestational age, 28 +/- 2 weeks; birth weight, 1030 400 g). A mean rate of 8 +/- 2 mu g/kg/min of dopamine raised SAP from 30 +/- 3 to 41 +/- 5 mm Hg (P < .05), and the pulmonary artery pressures from 25 +/- 5 to 32 +/- 8 mm Hg (P < .05). The SVC flow increased by 30% (from 130 +/- 40 to 170 +/- 44 mL/kg/min, P < .05). The left ventricular output and the end-diastolic and mean left pulmonary artery blood flow velocities did not change despite the increase in pulmonary artery pressure. Conclusion In preterm infants; with hypotension and PDA, dopamine (<10 mu g/kg/min) increases the systemic blood pressure and the systemic blood flow. Our results suggest that dopamine decreases left-to-right shunting across ductus arteriosus, caused by a rise in pulmonary vascular resistances. (J Pediatr 2008;153:790-4)