Comparison of Circulatory Effects between Arginine Vasopressin (AVP) and Dopamine in Conscious Newborn Goats

Abstract

By using conscious chronically instrumented newborn goats, the circulatory effect of arginine vasopressin (AVP) (20 mIU/kg/min) was studied, assuming a potential use for AVP to treat circulatory failure in the newborn, and the results were compared with those of dopamine (20 μg/kg/min). The AVP infusion decreased heart rate (HR) and cardiac output (CO) significantly, and increased systemic arterial pressure (SAP) and pulmonary arterial wedge pressure (PAWP) significantly, but did not change pulmonary arterial pressure (PAP) appreciably. The dopamine infusion did not change HR, SAP, and PAWP but increased CO and PAP significantly. Right atrial pressure (RAP) increased significantly in both groups. The pulmonary vascular resistance (PVR) increased significantly in both groups. The systemic vascular resistance (SVR) increased significantly in the AVP group, but did not change during experiments in the dopamine group. The calculated PVR/SVR ratios decreased significantly from the baseline value after initiation of the AVP infusion. In contrast, the dopamine infusion increased PVR/SVR ratios significantly throughout the experiments. Persistent pulmonary hypertension of the newborn (PPHN) is a syndrome characterized by right-to-left shunting of blood at the level of the foramen ovale and ductus arteriosus. AVP may reduce the shunting of blood by elevating only SAP selectively.