控制性肺膨胀对急性呼吸窘迫综合征家兔的肺力学和肺损伤影响

Effects of sustained inflation on pulmonary mechanics and lung injury in rabbits with acute respiratory distress syndrome

目的 探讨控制性肺膨胀 (SI)对急性呼吸窘迫综合征 (ARDS)家兔的肺力学和肺损伤影响。方法 利用肺泡灌洗法建立家兔ARDS模型 ,30只ARDS家兔随机分为SI组和非SI组。观察SI后 2h ,家兔肺力学及肺损伤的改变。结果 与非SI组相比 ,SI组在实施SI后 10、 30min ,1、 2h的平均气道压均明显降低。SI组 2h时的峰值气道压亦明显低于非SI组。与SI前比较 ,SI组实施SI后动态肺顺应性 (Cdyn)显著增加 ,SI前Cdyn为 (0 82± 0 11)ml/cmH2 O ,SI结束时达到最大 [(2 2 3± 0 4 )ml/cmH2 O],SI后 3h[(1 0 0± 0 0 6 )ml/cmH2 O]仍显著高于SI前水平。与非SI组比较 ,SI组 2h、 3h和 4h的Cdyn 均明显增加。非SI组肺损伤评分为 6 7± 2 6 ,SI组肺损伤评分显著降低 (5 0± 2 2 ,P <0 0 1)。结论 SI具有改善ARDS肺顺应性。

Objective To determine the effect of sustained inflaton(SI) on pulmonary mechanics and lung injury in rabbits with acute respiratory distress syndrome(ARDS).Methods SI was applied at pressures of 5 times of mean airway pressure(P m) for 20s on saline-lavaged anesthetized rabbits.Animal was divided into SI group( n =15) and non SI group( n =15).Pulmonary mechanics,gas exchange,and histology were measured 2h after applying SI.Results Compared with non-SI group,the mean airway pressure was markedly lower at 10min,30min 1h and 2h after SI.The peak airway pressure in SI group was lower than that in non-SI group at 2h after SI.Dynamic pulmonary compliance(C dyn )was (0 82±0 11)ml/cm H 2O at pre-SI in SI group,which increased to the highest level[(2 23±0 4)ml/cm H 2O] at the end of SI.At 3h after SI,C dyn was[(1 00±0 06)ml/cm H 2O],which was also higher than the pre-SI level.As compared with non-SI group,C dyn increased significantly at 2h,3h,and 4h in SI group.Histologically,Smith lung injury score was 5 0±2 2 in the SI group,which was less than the score in the non SI group (6 7±2 6).Conclusions SI could improve the pulmonary compliance and prevent lung injury in rabbit with ARDS. [