高原破片伤的创伤弹道特点

Ballistic feature of fragment wounds at high altitude

目的 了解高原球形和三角形破片分别击中猪后肢软组织的创伤弹道学特点。方法 在高原和平原，以53式滑膛枪分别发射1．03g钢球（射距20m）和0.37g三角形破片（射距10m），射击猪（15-25kg）后肢肌肉丰满处，避免伤及股骨及大血管，测定投射物初速和终点速度。伤后6小时测量伤道出、入口面积以及琥珀酸脱氢酶、ATP酶活性测定、永久伤道容积；切取距伤道壁0．5cm、1．5cm处肌组织进行显微病理观察；按照“4C”法判定伤道失活组织后行手术清创，测定切除坏死组织量。按照前述生物实验的致伤方法，分别在高原和平原射击密度与猪肌肉组织相似的肥皂块，观察空腔大小。结果高原破片终点速度较平原快，高原组伤道的出入口面积、伤道容积、伤道长度比值、切除坏死组织以及破碎肌组织的比例均大于平原组，高原球形和三角形破片伤组伤道肌纤维断裂和变性的程度均较平原组重，肌组织琥珀酸脱氢酶和ATP酶的活性下降，分别为平原组的26．86％和55、77％。高原射击肥皂空腔容积大于平原。结论高原破片伤的损伤程度较平原重，这与高原空气密度低，破片飞行阻力小，破片飞行速度较平原快，击中组织的瞬时空腔大等有关。

Objectives To study the ballistic feature of soft tissue impacted by steel spheres or triangular fragments at high altitude. Methods The steel spheres（1.03g） or triangle fragraents（0.37g） were shot at the hind legs of pigs with smooth gun at plateau,3658m above sea level（ the high altitude group）and 351m above sea level（ the plain control group） respectively. The wound tracks only passed through soft tissue with out involvement of large blood vesselsand femur, The terminal velocity of projectile was measured, The exit/entry areas and volume of wound track were measured,the muscle samples were obtained from wound track for pathological observation. Activities of succinate dehydrogenase （ SDH ） and ATPase were assayed,and the debridment was carried out according to surgical standard ‘4Cs＇ 6h after injury. The soap block simulating muscle tissue were shot by steel spheres and triangualr both at high altitude and plain. Results The terminal velocities of steel spheres and triangular fragments of the high altitude group were faster than these of the plain group. The exit/entry areas, the ratio of volume tolength of wound track, the ratio of excised necrotic tissue to length of wound track and the muscle fragment ratio in injured pigs of the high altitude group were larger than those of the plain group. The pathological changes of ruptured and degenerated muscle fibers in wound track of the high altitude group were more pronounced than those of the plain group. The activities of SDH and ATPase of wound track tissue of the high altitude group and the plain group were 26.86% and 55.77% ,respectively. The volumes of soap cavities of the high altitude was larger than that of plain group. Conclusion The damage degree of fragment wounds of the high altitude group was severer than those of the plain group,which may be contribute to low density of air at high altitude as a result of a faster velocity, low air resistance to projectiles and higger cavity in the muscle tissue.