家兔严重挤压伤后左室整体功能变化的实验研究

Experimental study of the change in left ventricular function after severe crush injury in rabbits

目的结合家兔肢体挤压伤后心肌组织超微病理改变情况,应用多功能复合心脏超声心动图技术评价家兔挤压伤后左心功能变化的情况。方法健康新西兰家兔42只,雌雄不拘,将其随机分为未被挤压组6只(对照组)和挤压伤组36只。挤压伤组应用自制挤压器具按标准制作挤压伤模型,依据解压时间不同将挤压伤组分为:解压即刻组、挤压伤后6 h、12 h、24 h、48 h和72 h,每组6只;应用多功能复合心脏超声测量各组心脏整体功能;透射电镜观察挤压伤前后心肌细胞超微结构改变。结果持续挤压6 h后解压,解压即刻组心脏整体收缩指标及舒张功能指标测值均降低,且与对照组比较差异有统计学意义(P<0.05);解压后6 h和12 h组左室收缩功能均较对照组显著下降(P<0.01);而左室舒张功能在解压后24 h下降最为明显(P<0.01)。电镜下观察可见挤压伤后心肌细胞线粒体水肿、嵴小梁断裂等改变。结论严重挤压伤后可致心肌组织继发损伤及心功能障碍,在解压后逐渐加重,至解压后12～24 h达到峰值,持续至伤后72 h后逐渐缓解;多功能复合心脏超声技术能够较精准、客观、快捷评估挤压伤后左室整体功能情况。

Objective Combined with myocardial tissues pathological changes ＇after crush injury in rabbits, to evaluate the changes in left ventricular function by multi-functional complex cardiac ultrasound. Methods Forty-two New Zealand rabbits were divided into control group （6 rabbits ） and crush injm3, group （36 rabbits）, and crush injury group was further divided into immediately, 6 h, 12 h, 24 h, 48 h and 72 h after pressure relief groups in each group including 6 rabbits. The cardiac function was measured by multi-functional complex cardiac ultrasound, and the myocardial cells changes were observed by electron microscopy. Results All the rabbits were extracted 6 h after crush, the cardiac systolic and diastolic function indexes in immediately after crush group were decreased than those in control group, there was significant difference（ P〈0.05 ）. The left ventricular systolic function in 6 h and 12 h after crush group were decreased than those in control group（ P〈0.01 ）, while the left ventricular diastolic function was most obviously decreased in 24 h after crush group （P〈0.01）. Mitochondrial swelling of myocardial cells could be observed by the electron microscopy. Conclusion In the early stage of crush injury, cardiomyocyte injury is induced, the damages are increased gradually, reach the peak after 12 -24 h and sustain to 72 h after crush injury. Multi- functional complex cardiac ultrasound can assess the damage of heart after crush injury accurately, objectively and rapidly.