高渗盐水对控制性降压下麻醉犬血容量和血流动力学的影响

目的研究小容量高渗盐水对控制性降压下健康麻醉犬血容量和血流动力学的影响。方法20只健康任意来源犬在全麻下随机分成两组,HS组输注4mL/kg7.5%NaCl,HES组输注15mL/kg6%HES行急性高容量血液稀释(AHH),两组均在30min内完成,同时微泵推注硝酸甘油行控制性降压至平均动脉压(MAP)下降40%。在血液稀释开始(B)和结束后5、30min(T1、T2)及1、1.5、2h(T3、T4、T5)分别监测MAP、中心静脉压(CVP)、肺动脉压(PAP)、肺毛细血管楔压(PCWP)、心输出量(CO);以上时点再取动脉血进行血气分析并记录血球压积(HCT)。结果HS组T1时扩增的血容量最大,达27.3%;HES组T1扩增的血容量为31.4%,T2时最大,达33.7%。HS组和HES组在AHH后,T1、T2的CVP和PCWP均较基础值显著升高(P<0.01);T1、T2时HES组的PAP显著高于HS组(P<0.05);AHH后两组CO均显著上升(P<0.01),且上升幅度HS组明显大于HES组(P<0.01)。结论4mL/kg7.5%NaCl在输注结束时和结束后2h,其血浆扩容效应与15mL/kgHES相当,其扩容峰值维持时间较短,血流动力学方面较HES溶液更稳定。

Effects of Hypertonic Saline on Blood Volume and Hemodynamics of Anesthetized Dog with Controlled Hypotension

Objective To investigate the effects of hypertonic saline on blood volume and hemodynamics of the dog under general anesthesia with controlled hypotension. Methods Twenty healthy mongrel dogs under general anesthesia were randomly allocated to receive 4 mL/kg 7.5% NaCl (HS group), and 15 mL/kg 6% HES (HES group),respectively within 30 min and the blood pressure was decreased 40% by using nitroglycerin during infusion. The mean arterial blood pressure (MAP), pulmonary capillary wedge pressure (PCWP),mean pulmonary arterial pressure(PAP), cardiac output (CO) as well as arterial hematocrit were measured at the beginning of acute hypervolemic hemodilution(AHH) (B), 5 min(T1),30 min(T2),1 h(T3),1.5 h(T4),2 h(T5) after AHH. Results The increase of blood volume in HS group was the greatest (27.3%) at T1. In HES group,the blood volume increased 31.4% at T1, and to the greatest(33.7%) at T2. At T1 and T2 during AHH, CVP, PCWP increased markedly in all dogs(P<0.01).PAP in HES group was higher than in HS group at T1,T2(P<0.05). After AHHD CO increased markedly(P<0.01),and the increase in HS group was higher than in HES group(P<0.01). Conclusion At the end of infusion and after infusion 2 h, the effects on blood volume expansion of 4 mL/kg 7.5% NaCl is similar to 15 mL/kg HES. The peak time of 7.5% NaCl effect on blood volume expansion is shorter,but its effect on hemodynamics is more stable than 6% HES.