Comparison of effects of 3 kinds of hydroxyethyl-starch with different molecular weight in resuscitation of uncontrolled hemorrhagic shock in rats

Objective To compare the effect of 3 kinds of 6% hydroxyethyl starch(HES)/0.9% sodium chloride with different molecule weight in early hypotensive resuscitation of uncontrolled hemorrhagic shock rats.Methods Uncontrolled hemorrhagic shock was produced by splenic injury with a transected branch of splenic artery.Thirty-two Sprague-Dawley rats were divided into 4 groups according to the resuscitation solutions infused before hemostasis: group Ⅰ,no resuscitation;group Ⅱ,6% hydroxyethyl starch 40 in normal saline;group Ⅲ,6% hydroxyethyl starch 130 in normal saline;group Ⅳ 6% hydroxyethyl starch 200 in normal saline.When the mean arterial pressure(MAP) reached 40 mmHg after injury,hypotensive resuscitation was begun with different HES/sodium chloride in different groups,to maintain the MAP at 50mmHg for 60 min(hypotensive stage).No fluid was infused in this stage in group Ⅰ.Then the splenic artery was ligated to get hemostasis,and animals in all groups were fully resuscitated with Lactated Ringer's and heparinized blood from donated rats for 2 hours.Hemodynamic parameters,blood loss,hematocrit,fluid volume and survival time were recorded.Results Compared with no resuscitation group,early hypotensive resuscitation significantly prolonged survival time,although with increasing blood losses.Moreover,the survival time of group Ⅲ and group Ⅳ were remarkably longer than that of group Ⅱ.The infusion volume before and after hemostasis in group Ⅲ and Ⅳ were remarkably less than that in group Ⅱ,with hematocrit higher than that in group Ⅱ.Hemodynamic effect of group Ⅲ and Ⅳ were remarkably better than that of group Ⅱ.Conclusion Hypotensive resuscitation with HES prolonged survival time in uncontrolled hemorrhagic shock rats compared with no resuscitation.HES with different molecular weight obtained different effects.The effect of HES130 and HES200 is better than HES40.