猪椎体火器伤早期死亡原因的实验研究

Experimental study on the cause of early death in gunshot injury to pigs spine

目的 建立家猪L2 椎体贯通火器伤实验模型,通过监测生命体征等指标变化及弹道损伤情况,分析高速椎体火器伤导致动物早期死亡的原因。方法 18只家猪随机分为2组:低速枪伤组(n =10 ) ;高速枪伤组(n =8)。全麻状态下建立L2 椎体侧方贯通伤模型,分别于伤前、伤后0 .5、1、2和3小时行血气分析、平均动脉压及脉率监测和损伤部位弹道CT扫描。结果 18只家猪中13只成功建立了L2 椎体火器伤模型,其中低速枪伤组6只、高速枪伤组7只。不同时相点2组动物平均动脉压进行性下降、心率进行性加快,但高速枪伤组较低速枪伤组变化幅度较大(P <0 .0 1) ;2组动物血pH、细胞外碱剩余(BE ecf)、血液碱剩余(BE B)、标准碳酸根浓度(SB)、实际碳酸氢根(AB)、氧分压(PaO2 )、二氧化碳分压(PaCO2 )和氧饱和度(SaO2 )呈进行性下降,但高速枪伤组出现的时间早、下降的幅度大(P <0 .0 5或0 .0 1) ;低速枪伤组动物3.5小时死亡率为16 .6 7%、高速枪伤组为85 .71% ,平均死亡时间分别为(7.1±1.1)小时和(3.5±0 .5 )小时,2组比较有显著性差异(P <0 .0 5和0 .0 1)。结论 枪弹的速度是决定损伤程度的重要决定因素之一,高速火器伤动物早期死亡的主要原因是弹道周围广泛创伤所致的失血性休克。

Objective To establish pig L 2 gunshot injury model,and investigate the cause of its early death.Methods Eighteen healthy pigs were randomly divided into 2 groups: L group,low velocity bullet group(n=8),and H groups,high velocity bullet group(n=8).L 2 were shot by assault rifle or snipe gun bullets.Before injury and at 0.5,1,2,3 hours after gunshot injury,the pH,base excess of blood(BE-B),base excess of estracellular fluid(BE-ecf),standard bicarbonate concentration(SB),bicarbonate(AB),partial pressure of oxygen(PaO 2 ),oxygen saturation(SaO 2 ),partial pressure of carbon dioxide(PaCO 2 ),mean arterial pressure(MAP) and pulse rate were determined respectively.Results The L 2 gunshot injury model was established successfully in 13 pigs.There was significant differences in MAP,pulse rate,PaO 2 ,PaCO 2 ,SaO 2 ,pH,BE-B,BE-ecf,SB and AB compared with those before injury in both groups(P<0.05 or 0.01).But the indicator in high velocity bullet group changed significantly as compared with that of low velocity bullet group(P<0.05 or 0.01),and there was a higher mortality and a shoter mean death time after injury in high velocity bullet group(P<0.05 or 0.01).Conclusion The bullet velocity is one of the most important factor in tissue wounding.The hemorrhagic shock is its main cause of early death.