Cheung P Y, Barrington K J, Pearson R J, Bigam D L, Finer N N, Van Aerde J E
The Perinatal Research Centre and Department of Pediatrics, University of Alberta, Edmonton, Canada.
Am J Respir Crit Care Med. 1997 Jan;155(1):32-7. doi: 10.1164/ajrccm.155.1.9001285.
The response of the systemic, pulmonary, hepatic and portal circulations to infusion of dopamine and epinephrine was studied in newborn piglets 1 to 3 d of age. Anesthetized animals were instrumented to measure cardiac index (CI), hepatic arterial flow, and portal venous blood flow. Catheters were inserted for measurement of systemic arterial pressure (SAP), pulmonary arterial pressure (PAP), and for sampling of arterial, portal venous, and mixed venous oxygen saturations and plasma lactate levels. Systemic, pulmonary and mesenteric vascular resistance indices (SVRI, PVRI, MVRI), and systemic and mesenteric oxygen extraction were calculated. Dopamine and epinephrine were infused in doses of 2, 10, 32 microg/kg/min and 0.2, 1.0, 3.2 microg/kg/min respectively, given in random order. Significant increases in SAP, PAP, and CI were demonstrated with 32 microg/kg/min of dopamine and the two higher doses (1.0 and 3.2 microg/kg/min) of epinephrine. There were no significant changes in SVRI and PVRI with dopamine infusions. Epinephrine at 3.2 microg/kg/min significantly elevated SVRI and PVRI. The SAP/PAP ratio was decreased with 32 microg/kg/min of dopamine whereas epinephrine did not affect the ratio. Dopamine had no significant effect on hepatic arterial flow, portal venous flow, or mesenteric vascular resistance. Epinephrine infusion at 3.2 microg/kg/min decreased portal venous blood flow, total hepatic blood flow, and hepatic oxygen delivery with an increase in calculated mesenteric vascular resistance. Systemic and mesenteric oxygen extraction were not affected by dopamine or epinephrine infusions. Plasma lactate levels were significantly elevated with epinephrine infusion 3.2 microg/kg/min. The differential responses of dopamine and epinephrine on pulmonary and mesenteric circulations may be significant in the pathophysiology and management of persistent fetal circulation and necrotizing enterocolitis.
对1至3日龄新生仔猪输注多巴胺和肾上腺素后，研究了体循环、肺循环、肝循环和门静脉循环的反应。对麻醉的动物进行仪器安装，以测量心脏指数（CI）、肝动脉血流量和门静脉血流量。插入导管以测量体动脉压（SAP）、肺动脉压（PAP），并采集动脉血、门静脉血和混合静脉血的血氧饱和度以及血浆乳酸水平。计算体循环、肺循环和肠系膜血管阻力指数（SVRI、PVRI、MVRI）以及体循环和肠系膜的氧摄取率。分别以2、10、32微克/千克/分钟和0.2、1.0、3.2微克/千克/分钟的剂量随机输注多巴胺和肾上腺素。输注32微克/千克/分钟的多巴胺以及较高的两个剂量（1.0和3.2微克/千克/分钟）的肾上腺素后，SAP、PAP和CI显著升高。输注多巴胺时，SVRI和PVRI无显著变化。输注3.2微克/千克/分钟的肾上腺素使SVRI和PVRI显著升高。输注32微克/千克/分钟的多巴胺使SAP/PAP比值降低，而肾上腺素对该比值无影响。多巴胺对肝动脉血流量、门静脉血流量或肠系膜血管阻力无显著影响。输注3.2微克/千克/分钟的肾上腺素会使门静脉血流量、肝脏总血流量和肝脏氧输送量减少，同时计算得出的肠系膜血管阻力增加。体循环和肠系膜的氧摄取率不受多巴胺或肾上腺素输注的影响。输注3.2微克/千克/分钟的肾上腺素后，血浆乳酸水平显著升高。多巴胺和肾上腺素对肺循环和肠系膜循环的不同反应可能在持续性胎儿循环和坏死性小肠结肠炎的病理生理学及治疗中具有重要意义。
