机械通气相关性肺损伤大鼠模型的建立与评价

Establishment and evaluation of rat model of ventilator-induced lung injury

目的建立机械通气相关性肺损伤大鼠模型并进行评价,确定建立机械通气相关性肺损伤大鼠模型的最适通气条件。方法选取成年雄性SD大鼠72只,体重250-300 g,随机分为A、B、C、D组（n=18）：对照组（A组,自主呼吸组）,小潮气量（VT）组（B组,VT=6 ml/kg）,常规VT组（C组,VT=10 ml/kg）,大VT组（D组,VT=40 ml/kg）,各组按机械通气时间（2、4、6 h）再随机分为3个亚组（n=6）。A组仅作气管切开插管,其余各组气管切开后接小动物呼吸机行机械通气,呼吸机参数均设置为RR 70/min,Fi O221%,PEEP 0 cm H2O。机械通气结束后处死大鼠,剖胸取右肺组织计算湿重干重比（W/D）,计算细胞凋亡指数,HE染色后光镜下观察肺组织病理学结果,并进行肺损伤评分。比较不同VT及通气时间条件下大鼠的肺损伤情况。结果与A、B、C组比较,D组通气2 h时开始出现肺损伤病理学表现,通气4 h时肺损伤评分、肺组织W/D和细胞凋亡指数均升高,差异有统计学意义（P〈0.05）。结论给予大鼠40 ml/kg VT通气4 h可以成功建立机械通气相关性肺损伤模型。

Objective To establish and evaluate the rat model of ventilator-induced lung injury,and to determine the best ventilation condition of rat model of ventilator-induced lung injury. Methods 72 adult male SD rat were selected,weight was 250-300 g,and they were randomly divided into group A,B,C and D(n=18).Control group(group A,spontaneous breathing group),low tidal volume group(group B,VT=6 ml/kg),routine tidal volume group(group C,VT=10 ml/kg) and high tidal volume group(group D,VT=40 ml/kg).Each group was divided into 3 subgroups(n=6) according to duration of mechanical ventilation(2 h,4 h and 6 h).group A was only given tracheotomy tube,the others were given small animal breathing machine to conduct mechanical ventilation after tracheotomy.The parameter of breathing machine was set as RR 70/min,Fi O2 was 21%,PEEP was 0 cm H2 O.The rat were sacrificed after the end of mechanical ventilation,W/D of right lung tissue taken by splitting chest was counted and cell apoptosis index was counted.The pathology results of lung tissue were observed under light microscope after HE staining.The score of lung damage was valued.Lung damage of rat at different tidal volume and duration of ventilation was compared. Results Compared with group A,B and C,lung damage pathology feature appeared after 2 h ventilation in group D and all of the lung damage score,W/D of lung tissue and cell apoptosis index was increased respectively,and the difference was statistical significance(P<0.05). Conclusion Rat is given 40 ml/kg of tidal volume and ventilation for 4 h can establish the model of ventilator-induced lung injury successfully.