新生兔重度胎粪吸入模型的制备

Model of severe meconium aspiration in newly-born rabbits

目的观察不同浓度胎粪悬混液对新生兔的影响,建立合适的机械通气胎粪吸入模型。方法 21只新生兔,随机分成25mg/ml浓度组,45mg/ml浓度组,65mg/ml浓度组以及对照组,分别由气管导管注入胎粪悬混液4ml/kg(对照组注入等量生理盐水),达到通气指征后,予以机械通气。观察各组8h内病死率、胎粪灌入前及胎粪灌入后30min肺顺应性(Cydn)、血气、氧合指数、肺组织大体病理情况及肺损伤病理评分。结果 25mg/ml组肺损伤小,8h内均未达到机械通气指征;45mg/ml组均在0.5h到机械通气指征,肺损伤较小;65mg/ml组在0.5h均达到机械通气标准,其病理显示肺损伤严重,实变及出血灶较大,病死率高。结论 45mg/ml组达到机械通气指征的时间较理想,肺损伤程度适中,适合做为机械通气模式等相关研究的重度胎粪吸入模型。

Objective Investigate the effects of meconium solutions on newly-born rabbits,and to establish a suitable model of meconium aspiration which needs to apply mechanical ventilation.Methods 21 newly-born rabbits were randomly divided into 25mg/ml concentration group（n=6）,45mg/ml concentration group（n=6）,65mg/ml concentration group（n=6）and the control group（n=3）.Meconium solutions were injected into the endotracheal tube by 4ml/kg in the first three groups while control group injected equivalent saline.Mechanical ventilation when achieved the ventilation indications.Observed the mortality within 8 hours in each group,lung dynamic compliance（Cydn）in the pre-and 30 minutes after meconium poured,blood gases,oxygenation index,lung tissue in general pathology and lung injury score.Results 25mg/ml concentration group were minimal lung injury,and failed to meet within the indications for mechanical ventilation in 8 h;45mg/ml concentration group were able to achieve the indications in 0.5 h,and had less lung injury;65mg/ml concentration group all reached the indications in 0.5h,its pathology revealed severe lung injury,pulmonary consolidation and hemorrhage focus were larger,and the mortality rate were higher.Conclusion 45mg/ml concentration group achieved the indications of mechanical ventilation in ideal time,the degree of the lung injury is appropriate.This group is a suitable one as a severe meconium aspiration model which can be applied in the research related to mechanical ventilation.