高碳酸血症对兔急性呼吸窘迫综合征保护作用初探

目的：通过观察肺组织病理学变化,探讨高碳酸血症对兔急性呼吸窘迫综合征（ARDS）的保护作用。方法：建立兔急性呼吸窘迫综合征动物模型并连接动物呼吸机,将兔随机分为两组,实验组给予外源性CO2吸入（浓度为6%）,实验对照组不给予外源性CO2吸入。分别观察2组兔肺组织湿重与干重比值及肺组织形态学变化。结果：（1）实验组兔的肺部水肿与炎性细胞浸润较对照组减轻,肺组织湿重与干重比值高于对照组;（2）两组可见广泛的灶性肺不张及肺成纤维细胞增生。结论：（1）高碳酸血症可减轻肺局部炎症,对兔急性呼吸窘迫综合征产生保护作用;（2）偏小的潮气量仍易导致ARDS兔广泛的灶性肺不张;（3）ARDS兔早期即可见到肺成纤维细胞增生。

Experimental Study on the Protective Effects of Hypercapnia to Rabbits with Acute Respiratory Distress Syndrome

Objective ： To investigate the protective effect of hypercapnia on rabbits with acute respiratory distress syndrome （ARDS） by using histopathological methods. Methods： ARDS Rabbit models were established and connected with animal ventilator, and mechanical ventilation was provided after tracheotomy. The ventilator parameters were： tidal volume 8ml/kg, R 51/min, PEEP 5 cmHO2, and FiO2 0.60. Rabbits were randomly divided into two groups, and those in experimental group were given CO2 （ FiCO2 0.06） while those in control group were not. The wet/dry weigh ratio and morphological change of lung tissue were observed and compared between the two groups in 180 minutes. Resuit： （1）Lung tissue edema and inflammatory cell infiltration were milder and lung tissue wet/dry weigh ratio was higher in experimental group than those in control group; （2）Extensive focal atelectasis and pulmonary interstitial fibrosis were found in both groups ; Conclusion ： （ 1 ） Hypercapnia can lighten lung parts and systemic inflammatory injury, and protect ARDS rabbits; （2） Too small tide volume can cause atelectasis in ARDS rabbits; （3）Pulmonary interstitial fibrosis can be found in the early period of ARDS.