多巴胺复合去甲肾上腺素对内毒素休克犬肾脏的影响

目的了解内毒素休克时低剂量去甲肾上腺素和多巴胺对肾血流量和肾功能的影响.方法21只犬(14-30kg)戊巴比妥钠麻醉,静脉注射内毒素2mg/kg,1h后将犬分成3组,Ⅰ组静滴去甲肾上腺素40ng.kg-1@min-1,Ⅱ组静滴多巴胺4μg.kg-1@min-1,Ⅲ组静滴去甲肾上腺素和多巴胺(剂量同上),给药1h停药并再观察2h.观察血流动力学(MAP、HR、CVP、PCWPCOSVISVR、)、肾血流量(电磁流量计)和肾功能(血清Na+、K+、肌酐、尿素氮、尿酸).结果休克后MAP显著下降(P＜0.01),CO明显减少(P＜0.01),肾血流量减少(P＜0.05),肾功能无显著改变.给予多巴胺、去甲肾上腺素和两药合用后MAP、SVI和CO增加,肾血流量无显著改变,肾功能基本无变化,仅给去甲肾上腺素2h及3h后尿素氮增加(P＜0.05),血肌酐显著增加(P＜0.01).结论低剂量去甲肾上腺素,特别是与多巴胺合用后能改善血流动力学,维持肾血流量,对肾功能无显著影响.

Effects of norepinephrine and dopamine on kidney during endotoxin shock in dogs

Objective To assess the effects of norephrine and dopamine on renal blood and renal function in a dog model of endotoxin shock. Methods Twenty-one mongrel dogs (weight 14-30 kg) were anesthetized with pentobarbital sodium and intubated. Spontaneous breathing was maintained. Swan-Ganz catheter was inserted via right external jugular vein. A 18G cannula was inserted via vein of the left upper limb for infusion of fluid and a 20G cannula in femoral artery for blood sampling and monitoring of arterial pressure. Abdomen was opened and right renal artery was exposed. A electromagnetic flowmeter (4mmφin interval diameter) was placed around the renal artery for measurement of renal blood flow. Shock was induced with intravenous administration of endotoxin 2mg/kg (LPS O55B5 Sigma). One hour after iv injection of LPS, the animals were divided into 3 groups with 7 dogs each: group Ⅰ (group NE) received norepinephrine infusion 40ng@ kg-1@ min-1 for 1h; group Ⅱ (group DA) received dopamine infusion 4μg.kg-1 @min-1 for 1h; group Ⅲ (group NE + DA) received NE 40 ng@ kg-1 @min-1 and 4 μg@ kg-1@min-1 for 1h. MAP, HR, cardiac output(CO), stroke volume index(SVI), CVP, PCVP, SVR, renal blood flow and renal function (serum Na+ , K+ , creatinine, urea nitrogen and uric acid ) were measured before LPS administration, lh after administration of LPS, at the end of norepinephrine and/or dopamine infusion, 1 and 2h after NE and/or DA infusion. Results MAP, CO and renal blood flow decreased significantly after LPS administration, but there was no significant change in renal function after LPS was given. After infusion of norepinephrine and/or dopamine MAP, SVI and CO increased significantly but there was little change in renal blood flow and renal function. Conclusions Low dose norepinephrine can improve hemodynamics and maintain renal blood flow and renal function especially when combined with dopamine during endotoxin shock in dogs.