对比常规体外循环与自体肺体外循环对肺功能影响的实验研究

The Empirical Study for the Effect to Lungs' Function Contrasting Conventional Extracorporeal Circulation to Extracorporeal Circulation with Autologous Lung as Oxygenator

目的探讨以自体肺取代人工肺的体外循环方法与常规体外循环对犬肺功能的影响。方法将12只杂种犬随机分为对照组及实验组(每组6只)。对照组在体外循环(CPB)期间使用膜式氧合器,实验组在CPB期间使用自体肺进行氧合,两组均阻断主动脉90 min、辅助循环30 min,CPB前及停止后15及60 min,监测气道峰压、肺血管阻力和肺静脉血氧分压,留取血标本做生化分析,对肺组织进行光、电镜观察。结果CPB后15和60 min,对照组气道阻力明显高于CPB前(P<0.05),实验组与CPB前比较差异无显著性(P>0.05),实验组CPB后15和60 min均低于对照组;CPB后15和60 min各组肺血管阻力均明显高于体外循环前(P<0.01),实验组明显低于对照组相应时间点(P<0.01);CPB后15和60 min各组氧指数均明显高于CPB前(P<0.01),实验组明显低于对照组相应时间点(P<0.01);实验组CPB后60 min肺泡-动脉氧压力差(P[A-a]O2)明显低于对照组(P<0.001)。实验组肺组织MDA含量及支气管肺泡灌洗液(PAL)中性粒细胞计数明显低于对照组(P<0.001,P<0.05)。实验组组织学改变明显轻于对照组(P<0.001)。结论常规体外循环后肺脏形态和功能有明显变化,自体肺体外循环较常规体外循环对犬肺形态和功能有良好保护作用。

Objective The aim was to determine the effect to lungs＇ function contrasting conventional extracorporeal circulation to extracorporeal circulation with autologous lung as oxygenator.Methods Twelve adult mongrel dogs were randomly divided into control group and study group.Cardiopulmonary bypass（CPB） using a membrane oxygenator（control group） or using the autologous lung（study group） for gas exchange was performed for 120 min in an alternating series of 12 mongrel dogs with the heart arrested for 90 min by crystalloid cardioplegia and 30 min reperfusion.Malondialdehyde（MDA） of lung tissue,alveolar-arterial oxygen gradient（PO2）,the ratio of white blood cell in BALf and lung function were measured at different time points（before CPB and after CPB 15 and 60 min）,lung biopsies were also made.Results The levels of airway resistance at the 15 th and 60 th minutes after CPB in control group were higher than the airway resistance levels before CPB（P〈0.05）.The levels of airway resistance at the 15 th and 60 th minutes after CPB in study group were lower than control group＇s at the same points（P〈0.01）.The levels of pulmonary vascular resistance at the 15th and 60th minutes after CPB in each group were lower than the levels before CPB（P〈0.01）.The levels at the 15th and 60th minutes after CPB in control group were higher than the levels at the same points in study group（P〈0.05）.The levels of PO2 at the 60th minutes after CPB in study group were lower than the levels in control group （P〈0.001）.The levels of MDA and neutrophil percentage in BALf at the 90th minutes after CPB in study group were lower than the levels in control group（P〈0.001,P〈0.05）.Morphological analysis revealed that the study group had a significantly lower percentage of pathological lesions and alveolar hemorrhage grade values than control group（P〈0.001）.Conclusion This study indicated that morphous and function damage occurs in lungs after conventional CPB.Extracorporeal circulation with autologous lung as oxygenator have protective benefit for pulmonary morphous and function.