大鼠窒息性心跳骤停-心肺复苏改良模型的评价

Evaluation of a rat model of asphyxial cardiac arrest and cardiopulmonary resuscitation

目的评价大鼠窒息性心跳骤停一心肺复苏改良模型。方法雄性SD大鼠15只，2～3月龄。体重350．400g，麻醉后经口气管插管，机械通气，连续监测心电图、MAP、HR、PgtCO2和直肠温度，并维持在正常范围内。静脉注射维库溴铵2mg／kg后机械通气，5～8min后再次静脉注射维库溴铵1mg／kg，1min后停止机械通气，制备窒息性心跳骤停模型。窒息8min后，开始药物和标准胸外按压进行心肺复苏（CPR）。记录从窒息到心跳骤停的时间、CPR到自主循环恢复的时间、拔管时间，并记录CPR成功及复苏成功后3d生存的情况。结果窒息8min可造成至少4～5min心跳骤停。CPR开始后2min内可逆转心跳骤停，使自主循环恢复（MAP〉60mmHg）。从窒息到心跳骤停的时间为（116±12）s，从CPR到自主循环恢复的时间为（42±12）s，拔管时间为（6．9±1．4）h。CPR成功率93％，复苏成功后3d生存率86％。与窒息前比较，自主循环恢复后即刻、10min时MAP、HR和PETCO2升高（p〈0．05或0．01）。结论大鼠窒息性心跳骤停-心肺复苏改良模型成功率及复苏成功后3d生存率高，模型稳定，可重复性好，可作为CPR研究的实验动物模型。

Objective To evaluate a rat model of asphyxial cardiac arrest and cardiopulmonary resuscitation （CPR）. Methods Fifteen male 2-3 month old SD rats weighing 350-400 g were anesthetized with intraperitoneal （IP） pentobarbital, intubated and mechanically ventilated with 70% 02. The external iliac artery and vein were cannulated and connected to a pressure transducer and micro-infusion pump respectively. The ECG, MAP, HR, PETCO2 and rectum temperature were continuously monitored and adjusted within normal range. The animals were then immobilized with 2 doses of vecuronium （2 mg/kg and 1 mg/kg） at 5-8 min interval. Asphyxia was induced by disconnecting the ventilator and clamping the trachea tube at the end of exhalation. After 8 min asphyxia, resuscitation was initiated by iv sodium bicarbonate and adrenaline and standard external CPR. The time from the beginning of asphyxia to cardiac arrest （CA）, the start of CPR to restoration of spontaneous circulation （ROSC）, the termination mechanical ventilation to extubation and the success rate of CPR and 3 d survival rate were recorded. Results Eight minute asphyxia resulted in more than 4-5 min CA which was reversed with 2 min by epinephrine and standard CPR and spontaneous circulation was stored with MAP 〉 60 mm Hg. The overall success rate of CPR and 3 d survival rate was 93% and 86% respectively. The MAP, HR, PETCO2 immediately and 10 min after ROSC were significantly higher than the baseline values before asphyxia. Conclusion Our CA and CPR rat model has high success rate of CPR and 3 d survival. The stability and repeatability of this model are good enough for CA-CPR study.