沙漠干热环境下创伤失血性休克大鼠模型的建立

Establishment of a rat model of traumatic hemorrhagic shock in dry hot desert environment

目的建立一种沙漠干热环境下创伤失血性休克大鼠模型。方法 90只雄性SD大鼠随机分为常温环境组、干热环境I组、干热环境II组3个实验组。麻醉后大鼠经打击及颈动脉放血,造成创伤失血性休克,使大鼠MAP(平均动脉压)达到(35±5)mm Hg水平,比较各组大鼠休克后3 h存活率,并对死亡大鼠及休克后3 h仍存活大鼠重要脏器取材进行病理学检查。结果休克后3 h常温环境组、干热环境I组(在休克模型建立成功后10 min内从沙漠干热环境转运到常温环境)、干热环境Ⅱ组(休克模型建立成功后仍放置在沙漠干热环境中)的存活率分别为90%、83.3%、0;干热环境I组与常温环境组存活率差异无显著性(P>0.05),常温环境组和干热环境I组存活率明显高于干热环境II组(P<0.01);病理学检查可见常温环境组、干热环境组I死亡大鼠和干热环境组II大鼠心、肺、肝组织水肿、变性、白细胞浸润、出血较广泛,细胞坏死较严重。结论本实验成功建立了沙漠干热环境下创伤失血性休克大鼠模型,同时提示沙漠干热环境能明显降低创伤失血性大鼠的存活率,伤后应立即转运后送。

Objective To establish a rat model of traumatic hemorrhagic shock in dry-hot desert environment.Methods Ninety male SD rats were randomly equally divided into three groups（ n = 30） ： the normal temperature environment traumatic hemorrhagic shock group（ normal temperature group）（ temperature 25℃,humidity 35%）,dry-hot traumatic hemorrhagic shock group I（ dry heat group I） and dry-hot traumatic hemorrhagic shock group Ⅱ（ dry heat group II）（ temperature 40℃,humidity 10%）. The rats were anesthetized,fixed,and intravenous indwelling needles were inserted into the right carotid artery,vein and the right femoral artery so as to make bleeding,and at the same time,fracture of the left hindlimb femur was made from the dropped steel wheel. The wounds were quickly bounded after injury.The mean arterial pressure was kept at 35 ± 5 mm Hg. The rats of group I was transferred into normal environment. The rats of group II were kept in the dry-hot environment continuously. The 3h-survival rates were calculated,and all the rats were sacrificed at 3 hours after the traumatic injury. Heart,lung and liver tissue samples were taken for histopathologicalexamination using HE staining. Results In the normal environment group,one rat died within less than 2 hours and 2rats died within 2-3 hours after injury. In the dry-hot environment group I,2 rats died within 1 hour and 3 rats died within2-3 hours. In the dry-hot environment group II,5 rats died within 1 hour and all the rest 27 rats died within 2. 5 hours.The survival rates of the normal temperature group,dry-hot groups I and II were 90%,83. 3%,and 0,respectively. There were no significant difference between the normal temperature group and the dry hot group I（ P〈0. 05）,but significant difference between the normal temperature group and dry-hot group I and the dry-hot group II（ P〈0. 01）. The pathological observation showed that the heart,lung and liver of the dead rats of the normal temperature group,dry hot groups I and in the dry hot group II had more severe edema,degeneration,leukocyte infiltration,wide-spread hemorrhage,and cell necrosis. Conclusions We have successfully established a rat model of traumatic hemorrhagic shock in dry-hot desert environment. The results of this study indicate that the hot desert environment may seriously decrease the survival rate of traumatic hemorrhagic shock rats. It suggests that in dry-hot environment,the traumatic hemorrhagic shock patients should be transported to a normal temperature and humidity environment as soon as possible.