低潮气量机械通气联合静脉-静脉体外膜肺氧合对羊急性呼吸窘迫综合征动物模型治疗作用初步研究

Therapeutic effect of low-tidal volume mechanical ventilation combined with V-V extracorporeal membrane oxygenation on a sheep model of acute respiratory distress syndrome:a preliminary study

目的:探讨体外膜肺氧合(extracorporeal membrane oxygenation,ECMO)对烟雾吸入性急性呼吸窘迫综合征(acute respiratory distress syndrome ARDS)羊PaO2、PaCO2及肺损伤严重程度的影响。方法:18只小尾寒羊随机均等分为NORMAL组、LVMV组与ECMO+LVMV组。LVMV组与ECMO+LVMV组通过烟雾暴露联合传统机械通气建立ARDS模型,ECMO+LVMV组给予低潮气量机械通气(low-tidal volume mechanical ventilation,LVMV)与ECMO联合治疗LVMV组仅给予LVMV治疗,整个研究期间NORMAL组仅予以LVMV。观察肺组织病理学、肺组织湿干重比、计算机断层扫描(computed tomography,CT)、动脉血气分析的变化。结果:T0时LVMV组与ECMO+LVMV组的胸部CT结果、血气分析结果、氧合指数均符合ARDS的诊断标准且组间无统计学差异;与LVMV组相比,T8、T16、T24时ECMO+LVMV组PaO2明显升高(PT8=0.000,PT16=0.001,PT24=0.001),PaCO2明显降低(PT8=0.000,PT16=0.003,PT24=0.000);T24时LVMV组与ECMO+LVMV组的肺组织湿干重比、病理结果及胸部CT结果无明显差异。结论:尽管LVMV联合静脉-静脉ECMO不能减轻烟雾吸入性ARDS羊肺组织损伤严重程度,但可明显升高PaO2、降低PaCO2,解决LVMV过程中氧合及PaCO2不理想的问题。

Objective:To investigate the effect of extracorporeal membrane oxygenation(ECMO)on arterial partial pressure of oxygen(PaO2),arterial partial pressure of carbon dioxide(PaCO2),and severity of lung injury in sheep with acute respiratory distress syndrome(ARDS)due to smoke inhalation.Methods:A total of 18 small-tailed Han sheep were equally and randomly divided into normal group,low-tidal volume mechanical ventilation(LVMV)group,and LVMV+ECMO group.The sheep in the LVMV group and the LVMV+ECMO group were treated with smoke exposure combined with conventional mechanical ventilation to establish a model of ARDS.The sheep in the LVMV+ECMO group were treated with LVMV combined with ECMO,and those in the LVMV group were treated with LVMV alone.The sheep in the normal group were given LVMV alone throughout the study.The changes in lung pathology,wet-todry ratio of the lung tissue,computed tomography(CT)findings,and arterial blood gas parameters were observed.Results:At T0,the chest CT findings,arterial blood gas parameters,and oxygenation index(OI)in the LVMV group and the LVMV+ECMO group met the diagnostic criteria for ARDS,and there were no significant differences in these indices between the two groups.Compared with the LVMV group at T8,T16,and T24,the LVMV+ECMO group had a significant increase in PaO2(PT8=0.000,PT16=0.001,PT24=0.001)and a significant reduction in PaCO2(PT8=0.000,PT16=0.003,PT24=0.000).At T24,there were no significant differences between the LVMV group and the LVMV+ECMO group in wet-to-dry ratio of the lung tissue,pathological results,and chest CT findings.Conclusion:In a sheep model of ARDS due to smoke inhalation,although LVMV combined with V-V ECMO cannot alleviate the severity of lung injury,it can significantly increase PaO2,reduce PaCO2,and solve the problem of unfavorable oxygenation and PaCO2 during LVMV.