The developmentally regulated hemodynamic effects of vasoactive medications have not been well characterized. We used traditional and near-infrared spectroscopy monitoring technologies and investigated the changes in heart rate, blood pressure, common carotid artery (CCA) blood flow (BF), cerebral, renal, intestinal, and muscle regional tissue O2 saturation, and acid-base and electrolyte status in response to escalating doses of vasoactive medications in normotensive anesthetized neonatal piglets. We used regional tissue O2 saturation and CCA BF as surrogates of organ and systemic BF, respectively, and controlled minute ventilation and oxygenation. Low to medium doses of dopamine, epinephrine, dobutamine, and norepinephrine increased blood pressure and systemic and regional BF in a drug-specific manner, whereas milrinone exerted minimal effects. At higher doses, dopamine, epinephrine, and norepinephrine but not dobutamine decreased systemic, renal, intestinal, and muscle BF, while cerebral BF remained unchanged. Epinephrine induced significant increases in muscle BF and serum glucose and lactate concentrations. The findings reveal novel drug- and dose-specific differences in the hemodynamic response to escalating doses of vasoactive medications in the neonatal cardiovascular system and provide information for future clinical studies investigating the use of vasoactive medications for the treatment of neonatal cardiovascular compromise.Abbreviations: BF, blood flow; BP, blood pressure; CBF, cerebral blood flow; CCA, common carotid artery; CrSO2 KrSO2 GrSO2 MrSO2, regional tissue O2 saturation of brain, kidney, gut, and muscle, respectively; NIRS, near-infrared spectroscopy; PaO2, partial arterial O2 pressure; Paco2, partial arterial CO2 pressure; rSO2, regional tissue O2 saturation; SpO2, arterial O2 saturation
展开▼
