肺挫伤复合内毒素血症肺损伤模型的建立及其早期肺炎症反应变化

目的 建立一种可用于实验研究的急性肺损伤（ALI）模型，观察其早期肺炎症反应特点，并探讨此模型下肺炎症反应与肺损伤伤情的关系。方法 首先以生物撞击机复制肺挫伤模型。经尾静脉注射内毒素（LPS），复制内毒素血症肺损伤模型；用同样的方法实施胸部撞击伤，然后注射LPS，建立肺挫伤复合内毒素血症肺损伤模型；观察三个模型下的死亡率、动脉血氧分压（PaO2）、肺含水率（RLW）及肺泡灌洗液（BALF）内多形核白细胞（PMN）和炎性介质变化。结果 肺挫伤复合内毒素血症肺损伤模型的48小时死亡率为57.5%，显著高于肺挫伤和内毒素血症肺损伤模型的死亡率；本模型致伤后早期PaO2降低和RLW升高程度均较其它两种模型明显，BALF内PMN计数和炎性介质水平出现显著变化，变化程度较其它两组明显。结论 肺挫伤复合内毒素血症肺损伤模型是一种严重的ALI模型，此模型的肺组织发生了明显的炎症反应；BALF中炎性介质于致伤后早期出现明显变化，创伤后早期肺炎症反应水平影响肺损伤程度及预后的重要因素。

Establishment of a lung contusion combined with endotoximia induced lung injury model and its early characteristics of lung inflammation response

Objective To establish a model of lung contusion combined with endotoxemia induced lung injury, and observate its characteristics of inflammatory response and evaluate the relationship between the inflammation response and the injury severity in this model.Methods Lung contusion and endotoxmic lung injury model were intruduced by bio impact apparatus and lipopolysaccharide injection through vail vein respectively. Lung contusion combined with endotoxemia induced lung injury model was introduced by lung contusion following lipopolysaccharide injection using same index of impact and same dose of lipopolysaccharide. Parameters such as mortality, RLW, PaO 2 were evaluated and inflammatory mediators in branchalveolar lavage fluid (BALF) were assayed. Results The mortality of this model during 48 hours was 57.5% , that was significantly higher than that of other two models. The elevation of RLW and the decrease of PaO 2 were more significant in lung contusion combined with endotoxemia acute lung injury model than in other two models. Following injury, an obvious inflammatory response was observed by BALF mediators assay in this model.Conclusion Lung contusion combined with endotoxemia induced lung injury model is a acute lung injury model with a severity that is more significant than lung contusion model or endoxemia lung injury model. Evident inflammatory response that is presented by inflammatory mediators in BALF processes in lung tissue following trauma. The level of lung inflammatory response following trauma is the important element that influence the severity of lung injury and outcome.