吸入不同浓度氧全麻下肺叶手术时氧自由基及肺超微结构的变化

Clinical observation on oxygen free radical and ultramicroscopic structure of human lung with difference concentration of oxygen during pneumonectomy

目的：观察吸入不同浓度氧肺叶手术时早期氧自由基和肺超微结构的变化。方法：３１例择期肺叶手术患者，随机分为两组Ｏ组（ＦｉＯ２＝１，ｎ＝１６），Ｎ组（吸入Ｏ２∶Ｎ２Ｏ＝１∶１，ｎ＝１５）。两组麻醉方法基本相同，观察ＳＯＤ和ＭＤＡ在麻醉前、麻醉后２小时、手术结束时和术后２４小时的变化，观察肺切片组织在光镜和电镜下肺超微结构的变化。结果：两组用氧时间ＳＯＤ和ＭＤＡ组间对比，以及ＭＤＡ两组组内对比均无统计学差异（Ｐ＞０．０５）；术后２４小时ＳＯＤ和ＭＤＡ均恢复术前水平。Ｏ组ＳＯＤ麻醉后２小时和手术结束时与术前比较明显下降（Ｐ＜０．０１和Ｐ＜０．０５），Ｎ组ＳＯＤ仅麻醉后２小时下降（Ｐ＜０．０５）。经半定量统计，电镜和光镜肺超微结构病理改变明显，各项指标Ｏ组均较Ｎ组显著。结论：①ＦｉＯ２≥０．５麻醉时，高氧肺损伤早期的生化改变可能主要是Ｏ－２产生增多，ＳＯＤ下降；②ＦｉＯ２≥０．５在５小时内是安全的；③本研究进一步证明全麻时吸入Ｎ２Ｏ－Ｏ２优于纯氧吸入。

Objective:In order to investigate early stage change of oxygen free radical and ultrastructure of human lung with high concentration of oxygen during general anesthesia.Method:Thirty one patients undergoing pneumonectomy,were randomly divided into two groups:group O(FiO 2=1.0,n=16)and group N (FiO 2=0.5,O 2∶N 2=1∶1,n=15).The times of inspiring oxygen were similar in 2 groups .Superoxide dismutase (SOD) activity and malonydialdehyde (MDA) level were measured before anesthesia,2 hours during anesthesia, at the end of the operation and 24 hours after operation in two groups.Ultramicroscopic structure of human lumg of two groups had been investigated with optical and electron microscopy.ResultPlasma SOD activity of group O was significantly decreased 2 hours during anesthesia and at the end of the operation(P<0 01 and P<0 05),but plasma SOD activity of the group N was decreased significantly only at two hours during anesthesia (P<0 05).The pathological ultramicroscopic change of the pulmonary tissue of group O was worse than that of group N Conclusion FiO 2 more than 0.5 and the respiratory time less than 5 hours are safe for those patients, and during general anesthesia inspiring mixture of N 2O O 2 is better than pure oxygen.