自体肺体外循环对肺功能的保护作用

Protective effect of extracorporeal circulation with autologous lung as oxygenator on lung function

目的:探讨以自体肺取代人工肺的体外循环(CPB)方法对犬肺功能的保护效果。方法:12只杂种犬随机分为对照组及实验组(每组6只)。对照组在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90min、辅助循环30min,CPB前及停止后15及60min监测气道峰压、肺血管阻力和肺静脉血氧分压,留取血标本进行生化分析,对肺组织进行光、电镜观察。结果:CPB后15和60min,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60min均低于对照组(P<0.05);CPB后15和60min各组肺血管阻力均明显高于CPB前(P<0.01),实验组明显低于对照组相应时间点(P<0.01);CPB后15和60min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60min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:CPB后肺脏形态和功能有明显变化,自体肺体外循环对犬肺形态和功能有良好的保护作用。

Objective To determine the protective effect of extracorporeal circulation with autologous lung as oxygenator to lung function in dogs.Methods Twelve adult mongrel dogs were randomly divided into control group and experimental group.Cardiopulmonary bypass （CPB） using a membrane oxygenator （control group） or using the autologous lung （experimental 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 （P[A-a]O2）,the ratio of white blood cells in BALf and lung function were measured at different time points （before CPB,15 and 60 min after CPB）,lung biopsies were also made. Results The levels of airway resistance at 15 and 60 min after CPB in control group were higher than the airway resistance levels before CPB （P〈0.05）.The levels of airway resistance at 15 and 60 min after CPB in experimental group were lower than those in control group at the same points （P〈0.01）.The levels of pulmonary vascular resistance at 15 and 60 min after CPB in each group were lower than the levels before CPB （P〈0.01）.The level at 15 and 60 min after CPB in control group was higher than that in experimental group at the same points（P〈0.05）.The levels of PaO2/FiO2 at 15 and 60 min after CPB in each group were higher than the levels before CPB （P〈0.01）.The levels of PaO2/FiO2 at 15 and 60 min after CPB in control group were lower than those in experimental group at the same points（P〈0.05）.The levels of P[A-a]O2 at 60 min after CPB in experimental group were lower than those in control group（P〈0.001）.The levels of MDA and neutrophil percentage in BALF at 90 min after CPB in experimental group were lower than those in control group （P〈0.001,P〈0.05）.Morphological analysis revealed that in experimental group the percentage of pathological lesions and alveolar hemorrhage grade values was lower than those in control group （P〈0.001）.Conclusion Morphous and function have obvious changes in lungs after CPB.Extracorporeal circulation with autologous lung as oxygenator has protective effect on pulmonary morphous and function.