大鼠冲击伤复合缺氧肺损伤特点

Characteristics of lung injuries in rats with blast injury combined with hypoxia

目的 探讨大鼠冲击伤复合缺氧时肺损伤的特点。方法 健康Wistar大鼠116只，随机分为正常对照组（NG）、单纯冲击伤组（BI）、冲击伤复合缺氧（12．5％O2）Ⅰ组（BHI）和冲击伤复合缺氧（10．0％O2）Ⅱ组（BHⅡ），动态观察大鼠伤后6h内的一般情况、死亡率、肺组织病理改变等。结果 BⅠ组、BHⅠ和BHⅡ组伤后6h的死亡率分别为2．8％，11．1％和41．7％，死亡均发生于伤后3h内。冲击伤后大鼠出现呼吸急促和轻度烦躁不安；当伴有缺氧时，呼吸困难和烦躁明显加重，肺出血、水肿明显重于单纯冲击伤组；这些均与缺氧程度有关。光镜下病理学改变主要为肺出血、中性粒细胞浸润、肺泡内大量红细胞和纤维渗出物，电镀下可见明显肺泡壁断裂、肺泡Ⅱ型上皮细胞板层小体减少等，这些改变均以冲击伤复合缺氧大鼠更为明显。结论 冲击伤复合缺氧后伤情明显加重，死亡率显著增加。主要表现为肺出血水肿、呼吸功能障碍，所伴缺氧程度越高，肺损伤越显著。对冲击伤复合缺氧者的救治首先要做到尽早脱离缺氧环境，同时高度重视肺出血、水肿的救治，尽快改善呼吸功能。

Objective To study the characteristics of lung injury in rats with blast injuries combined with hypoxia. Methods A total of 116 healthy Wistar rats were divided randomly into four groups： normal control group （Group NG）, blast injury group （Group BI）, blast injury combined with hypoxia group Ⅰ （ 12.5% 02 ） （ Group BHⅠ ） and blast injury combined with hypoxia group Ⅱ （ 10.0% O2 ） （ Group BH Ⅱ ）. The behavior, mortality and pathologic changes were monitored for 6 hours after injury. Results Death occurred 3 hours after injury, with death rates of 2.8%, 11.1% and 41.7% in Groups BI, BHⅠand BH Ⅱ respectively. Rats had shortness of breath and slight dysphoria after blast injury. When accompanied by hypoxia, shortness of breath, dysphoria, pulmonary hemorrhage and edema, which were related with the degree of hypoxia, were significantly aggravated. Light microscope showed following pathologic changes included pulmonary hemorrhage, neutrophil infiltration, increased amount of erythrocyte and fibrous exudates and electron microscope showed broken alveolus wall and decreased lamellar body count in the type Ⅱ alveolar epithelial cells. Conclusions Blast injury combined with hypoxia would significantly aggravate lung injury and increase the mortality. The main pathologic changes are pulmonary hemorrhage, edema and respiratory dysfunction. There is a positive correlation between the degree of hypoxia and lung injury. The first aid for blast injury combined with hypoxia includes removal from the hypoxic environment, treatment of pulmonary hemorrhage and edema and improvement of the respiratory function as early as possible.