【作者】 刘瑞峰；

【导师】 刘彦普；

【作者基本信息】 第四军医大学 ， 口腔临床医学， 2002， 硕士

【摘要】 近年来，爆炸伤的发生率不仅在战争中较以前有所增加，在和平年代较以前也有所增加。爆炸伤是一种不同于火器伤的特殊类型创伤，其发生机理是：爆炸物爆炸后，产生高温高压的气体并高速向外界扩散形成冲击波，初速度可达7000m／s以上，中心温度可达3000℃以上，同时产生大量的破片，共同致伤机体组织。 本实验采用一种新型的爆炸球作为爆炸源，建立家兔颌面部爆炸伤动物模型，观测冲击波的致伤作用。采用不同装药当量和不同爆炸距离致伤实验动物，使用PVDF薄膜压力传感器及示波器记录实验力学数据。 本实验观察颌面部爆炸伤后家兔颈部大血管的损伤情况，并应用放射免疫法检测颌面部爆炸伤早期过程中血浆、肺脏、脑皮层内血栓素B₂及6-酮-前列环素F₁的水平，探讨爆炸伤后其水平及比值变化的意义。 爆炸球引爆后，家兔颌面部受到爆炸物冲击波的作用，以局部损伤为最重，造成软组织撕裂伤，并可发生骨折。使用不同当量的爆炸球以及爆炸球与家兔皮肤距离不同时爆炸造成的损伤伤情不同，当量大，距离近，伤情明显重，家兔甚至死亡。0.125gTNT当量的爆炸球表面距离家兔左侧下颌角皮肤2mm爆炸时，下颌角皮肤所受压力的峰值为842MPa，达到峰值时 第四军医大学硕士论文 间为 l石卜，平均受压时间19石卜；颈总动脉平下颌骨下缘平 面所受压力的峰值为34MPa，达到峰值时间为2石Ps，平均受压 时间14石卜S。 形态学观察发现家兔左侧颈总动脉、颈外静脉壁损伤，血 管内皮细胞排列紊乱，部分内膜脱落，中膜层弹性纤维及平滑 肌细胞中断，形成裂隙甚至空腔，并有血细胞嵌人，这为创伤 后发生假性动脉瘤提供了理论支持。颈外静脉内血栓形成，颈 总动脉内形成附壁血栓，24h内是血栓形成的高峰期。 从致伤即刻开始，血浆、肺脏、脑皮层内血栓素AZ 和前 列环素乙的水平及比值逐步上升，TXAZ和PGIZ在血液中的半 衰期很短，很快转变为稳定的非活性产物血栓素BZ及6－酮－前 列环素广u，一般测量后者的含量代表前者。TXAZ和PGIZ及 其比值分别在 6 h、6 h、2 4 h达到峰值，以后逐步呈下降趋势， 并恢复至伤前水平。这表明血小板活化，血管内皮细胞功能下 降，血液处于高凝状态，利于并促进了血栓的形成。TXA。有 较强的缩血管功能，加重了肺脏及脑组织的损伤。颌面部爆炸 伤后监测血浆TXBZ及6－kCt。－PGFIu的含量有一定的临床意义。更多还原

【Abstract】 In recent years, the incidence of explosive injury has greatly increased both in war times and in peaceful times, and during the detonation maxillofacial region was often involved.Detonation of explosives can generate certain amount of atmosphere with high temperature more than 3000癈 and high velocity more than 7000m/s near the source, which can injure bodies together with the fragments generated by the detonation.The objective of this study is to establish a type of animal model of maxillofacial explosive injury, which increases the standardization of studies on explosive injury. In this study we adopt a novel kind of spherical explosive produced by NINT, and we measure pressures and strains and accelerations with different kinds of sensors and oscilloscopes. Pressures outside and inside of soft tissues can be precisely measured, as well as strains and accelerations of bones.In the animal models of maxillofacial explosive injury with the novel explosives, parameters of all kinds can be measured precisely. The model can be duplicated conveniently and through which we can better studies on animal maxillofacial explosive injury. We suggest using the explosive of 0.125g TNT equivalent, with the radius of 2.5 nun, in rabbit models of maxillofacial explosive injury. When 0.125g TNT equivalent explosive detonates 2 nun away from skin of maxillofacial region , the peak value of the pressure on the skin is 842MPa, and the time of thepeak is 2.6ps, and the pressure lasts only 19.6|as. The peak value of the pressure on the common carotid artery is 34MPa, and the time of the peak is 2.6us, and the pressure lasts only 14.8|us.Both walls of veins and arteries were damaged. Endothelial cells of some part of the vessels disappear and thrombosis was found in external jugular veins after injury. Crevice or cavity can be found in tunica medium, which may account for the possible reasons of pseudo-aneurysm formation after injury.The studies show TXB2 and 6-keto-PGFiu levels and the ratio of them in plasma, lung and brain tissues changes during the early stage of maxillofacial explosive injury. The stable metabolites of thromboxane A2(TXA2)and prostacyclin(PGl2), TXB2 and 6-keto-PGF] ?,in the blood serum were measured before and after injury. TXB2 and 6-keto-PGFi a levels and the ratio significantly increased after injury, and reached the peaks at 6h or 24h after injury, and reduced to the normal levels at the third day. During maxillofacial explosive injury, the increase of TXA2 and PGI2 levels and the ratio is owing to the damage of capillary endothelia in soft tissues near the wound or in lungs or in brain, and the activation of platelets, then thrombus can form in blood vessels.更多还原