不同复苏压力对非控制性出血休克复苏效果的影响

Effect of different resuscitation pressure on uncontrolled hemorrhagic shock in rats

目的利用大鼠非控制性出血休克模型探讨非控制性出血休克早期不同复苏血压对休克复苏效果的影响。方法Wistar大鼠64只，随机分为8组，每组8只，戊巴比妥钠麻醉，断脾法复制非控制性出血休克模型，将血压降至40或50mmHg。动物分为3个处理阶段，第1阶段模拟院前救治阶段，用2：1乳酸林格液和6％的右旋糖苷分别以40、50、60、70、80、100mmHg血压复苏动物，此期维持1h，以假手术组和院前不复苏组作为对照；第2阶段模拟医院确定性处理，结扎脾动脉止血，输血输液将血压恢复至100mmHg，维持2h；第3阶段，维持2h，观察第1阶段不同压力复苏对休克复苏效果的影响。观察指标包括血流动力学指标、血球比容和动物存活时间。结果院前急救采用高压复苏（80、100mmHg）动物存活时间短，一半动物在院前急救阶段很快死亡，血球比容低，血流动力学指标差，而采用低于70mmHg（50、60mmHg）的血压复苏，动物存活时间延长，血液稀释轻，血流动力学指标明显优于高压复苏组，但太低的输注压力（40mmHg）也不利于休克复苏，动物存活时间缩短，死亡率增高。结论针对非控制性出血休克，院前急救采用高压复苏会增加血液丢失，影响后期复苏效果；适当低压复苏（50～60mmHg）有利于保持动物的血流动力学稳定，改善后期复苏效果；但太低的输注压力因影响组织灌流也不利于休克复苏。

Objective To compare the effect of different resuscitation pressure on resuscitation outcome of uncontrolled hemorrhagic shock. Methods Sixty four Wistar rats were divided into 8 groups（n=8/group） and anesthetized with sodium pentobarbital. Uncontrolled hemorrhagic shock was produced by spleen amputation and the mean arterial blood pressure （MAP） was drop to 40 or 50mm Hg. The management was divided into three phases. The first phase mimicked the prehospital emergency treatment, during which the shocked rats were resuscitated with lactated Ringer＇s solution and 6 % dextran to a MAP at 40,50,60,70,80 and 100mm Hg for lh respectively, sham operated group and unresuscitated group were as control group. The second phase mimicked the definitive treatment of hospital, during this phase, the spleen artery was ligated and the rats was resuscitated to a MAP at 100mm Hg for 2h with fluid and blood. The third phase was 2h resuscitation effect observing period. The observed parameters included mean arterial blood pressure（MAP）, hemodynamic parameters, hematocrit and animal survival time. Results The animals in the hypertensive （80,100mm Hg） resuscitation groups at early treatment had a short survival time,half of animals died at the first stage. They had a lower hematocrit and hemodynamies. In contrast, the animals in the hypotensive （50,60,70mm Hg） resuscitation groups had a longer survival time. Their hemodilution was not severe and their hemodynamics were superior to the hypertensive resuscitation groups. But too low resuscitation pressure （40mm Hg） was not good to shock resuscitation, the animal survival rate was not high,the survival time was lower than 50,60 and 70 mm Hg groups and close to 80mm Hg group. Conclusion Hypertensive resuscitation for uncontrolled hemorrhagic shock in prehospital phase will increase the blood loss and interfere with the resuscitation effect. Proper hypotensive resuscitation（50--60mm Hg） in early stage will benefit to the stabilization of hemodynamics and shock resuscitation. But too low resuscitation pressure was not good to shock resuscitation because of insufficient tissue perfusion.