L-精氨酸对兔大量输注库血后酸碱平衡和血栓弹力图的影响

目的：探讨兔大量输注库血后酸碱平衡和血栓弹力图（thromboelastograph，TEG）的变化以及L-精氨酸（L-arginine，L-Arg）对其的影响。方法：普通级新西兰大白兔50只，其中20只用来抽取全血做为实验用血，其余30只随机分为3组（n=10）。对照组：对实验动物进行放血（血容量的20%），维持30 min后输入等量库血，输血前5 min给予和25% L-Arg 300 mg/kg同等容量的生理盐水(1.2 mL/kg)；假手术组：进行与对照组相同的麻醉、有创操作和监测，但不进行放血和输血的处理，在与对照组相同的时间给予25% L-Arg 300 mg/kg。L-Arg组：所有操作同对照组，只将生理盐水的输注改为25% L-Arg 300 mg/kg。各组动物分别于麻醉及有创操作完成后稳定10 min（T0）、放血结束即刻（T1）、输血结束即刻（T2）、输血结束60 min（T3）和输血结束120 min（T4）5个时点抽血进行动脉血气分析，于T1和T4时点抽血进行TEG的测定。结果：对照组和L-Arg组的血pH值先降后升，其中对照组T2时点血pH值显著低于T0和T1（P<0.05）；假手术组各时点的血pH值均无明显变化。3组实验动物的碱剩余（base excess，BE）值持续降低，其中对照组和L-Arg组T2~T4时点的BE值均显著低于T0（P<0.05），假手术组T4时点的BE值明显低于T0时点（P<0.05）。对照组血乳酸（lactate，Lac）含量无明显变化；假手术组和L-Arg组血Lac含量逐渐下降，T3和T4时点的血Lac含量明显低于T0（P<0.05），且T1~T3时点的血Lac含量均明显低于对照组（P<0.05）。3组实验动物T0至T4时点的TEG组内和组间差异均无统计学意义（P>0.05）。结论：实验兔输血前给予L-Arg 300 mg/kg可以明显改善组织灌注，但对酸碱平衡影响不大；L-Arg对TEG的影响还需进一步实验证实。

Effects of L-arginine on acid-base balance and thromboelastograph in rabbits after banked-blood transfusion

Objective:To investigate the effects of L-arginine(L-Arg) on acid-base balance and thromboelastograph(TEG) in rabbits after banked-blood transfusion.Methods: Fifty New Zealand white rabbits,of which 20 were banked-blood donors,and the remaining 30 were randomly divided into 3 groups(n=10).Control group: hypovolemic models were made through blood loss by 20% of blood volume,and were retransfused with equal volume of banked-blood(14 days) 30 min later.Normal saline 1.2 mL/kg was given intravenously 5 min before transfusion;Sham operation group: the rabbits only received 25% L-Arg 300 mg/kg(1.2 mL/kg) intravenously at the same time-point as control group,without blood loss and banked-blood transfusion;L-Arg group: the rabbits received the same procedure as control group,equal volume of L-Arg was given as the control instead of normal saline.Blood gas /electrolyte analyses were determined before(T0) and after blood loss(T1),immediately after banked-blood transfusion(T2),60 min(T3) and 120 min(T4) after banked-blood transfusion.TEG were checked only at T0 and T4.Results: In control group and L-Arg group,pH values were declined after blood loss and banked-blood transfusion,and then increased after the first drop.The pH value of control group at T2 was significantly lower than that at T0 and T1(P<0.05).Base excess(BE) values continued to decrease from T0 to T4 of the three groups,which were significantly lower at T4 than at T0 in sham operation group(P<0.05).As to the concentration of blood lactate(Lac),there were no significant differences between the three groups at T0.In sham operation group and L-Arg group,Lac decreased from T0 to T4(P<0.05),which was significantly lower than that of control group at the same time-point(P<0.05).The TEG had no significant difference within and among the groups at T0 and T4(P>0.05).Conclusion: L-Arg 300 mg/kg intravenous injection can improve tissue perfusion in rabbits receiving banked-blood transfusion,while there was little effect on acid-base balance and TEG.