出血未控制性休克限制性液体复苏机制的探讨

Mechanism of better result of limited resuscitation in a model of uncontrolled hemorrhagic shock

目的 探讨出血未控制性休克限制性液体复苏提高复苏效果的机制。方法 5 4只 Wistar大鼠应用 Krausz等人制作的标准脾脏损伤 +切断脾中部一动脉分支制作重度未控制出血性休克模型 ,休克后依据维持平均动脉压 ( MAP)的不同随机分为 4 0、5 0、6 0、80和 10 0 m m Hg( 1mm Hg=0 .133k Pa)组 (分别为RS4 0、RS5 0、RS6 0、RS80、RS10 0组 )和假手术组 ( SS组 ) ,当 MAP降至 4 0 m m Hg时开始应用平衡盐液复苏 ,分别维持上述相应的 MAP,4 5 m in( T4 5点 )后结扎止血 ,再应用平衡盐液 +全血 ( 2∶ 1)复苏 ,使 MAP尽量维持在 10 0 mm Hg,2 h后 ( T16 5点 )停止输液 ,观察 4 h( T4 0 5点 )。于 T0点、T4 5点、T16 5点和 T4 0 5点抽血样送检 ,测定血乳酸 ( BL )、碱缺失 ( BE)和血细胞比容 ( Hct) ;于 T4 0 5点取少量肝组织测定组织血流量、ATP酶、丙二醛 ( MDA)和总抗氧化能力 ( T AOC)。结果 随着维持 MAP的增高 ,血 Hct、肝组织 ATP酶、T AOC和组织血流量逐渐降低 ,而 MDA、BL和 BE却逐渐增高。在 T4 5和 T4 0 5点 ,RS80和 RS10 0组的 Hct明显低于 SS、RS5 0和 RS6 0组 ( P均 <0 .0 5 ) ;在 T4 0 5 ,RS80和 RS10 0组的 BE和 BL 明显高于其他 4组 ( P均 <0 .0 5 ) ,MDA明显高于 SS、RS4 0和 RS5 0组 (

Objective To investigate the mechanism of better result of limited resuscitation in a model of uncontrolled hemorrhagic shock. Methods Uncontrolled hemorrhagic shock was produced in 54 rats by a standardized massive splenic injury with transection of the middle branch of splenic artery (MSIA). The rats were randomly assigned to six groups ( n =6) by maintenance of the level of mean arterial pressure (MAP): shamoperated group(SS), 40 (RS40), 50 (RS50), 60 (RS60), 80 (RS80) and 100 mm Hg (RS100, 1 mm Hg =0 133 kPa). When the MAP reached 40 mm Hg, resuscitation was begun. Ringer's solution was continued as needed to maintain the following desired endpoints for 45 minutes (T45 point):MAP of 40, 50, 60, 80 and 100 mm Hg. After the bleeding was controlled, resuscitation was continued with Ringer's solution and whole blood (2∶1) to raise the MAP to 100 mm Hg for 120 minutes (T165 point), followed by a 240 minutes observation period (T405 point). All animals were observed for 240 minutes or till death. The blood samples were withdrawn from artery for hematocrit (Hct), blood lactate (BL), base excess (BE) at T0, T45, T165, T405 points. At the end of the experiment, a small amount of hepatic tissue was collected for measuring tissue blood perfusion, total antioxidative capacity (TAOC), Na +K +ATPase, and malondialdehyde(MDA) . Results At T45, T405 points, Hct in SS, RS50 and RS60 were significantly higher than in RS80 and RS100( P <0 05). At T405 point, BL and BE levels in RS80 and RS100 were significantly higher than that of the other groups( P <0 05). The contents of MDA in SS, RS40, and RS50 were significantly lower than in RS80 and RS100( P <0 05). TAOC level,Na +K +ATPase were significantly lower in RS80 and RS100 than that in the other groups. Blood perfusion was significantly lower in RS80 and RS100 than that in SS, RS40, and RS50. Conclusion In the setting of uncontrolled hemorrhagic shock, limited resuscitation could balance well the needs of organ perfusion and decrease lactate level. It might also exert a protective effect against ischemia/reperfusion injury to liver tissue.