慢性阻塞性肺疾病患者肺气肿空间分布对肺功能及临床严重程度的影响

Influence of spatial distribution of emphysema on pulmonary function and clinical severity in chronic obstructive pulmonary disease patients

目的探讨慢性阻塞性肺疾病(COPD)患者肺气肿空间分布对肺功能及临床严重程度的影响。方法对84例COPD患者行胸部MSCT,应用COPD分析软件自动测量各肺叶低密度区容积百分比(LAA%),分析各肺叶LAA%与肺功能指标的相关性。根据肺气肿异质性指数将患者分为无肺气肿组及肺气肿组,其中肺气肿组又分为上叶肺气肿为主亚组和下叶肺气肿为主亚组;比较2组肺功能指标以及肺气肿组内2亚组临床严重程度差异。结果各肺叶LAA%均与单次一氧化碳弥散量实测值占预计值的百分比(DLcoSB%_(pred))呈负相关;除右肺中叶外,其余肺叶LAA%均与第1秒用力呼气量/用力肺活量(FEV1/FVC)、FEV1的实测值与预计值的百分比(FEV1%_(pred))呈负相关,与响应频率(Fres)呈正相关。2组间肺功能指标比较差异均有统计学意义(P均<0.05);肺气肿组内2亚组间FEV1%_(pred)及FEV1/FVC差异有统计学意义(P均<0.05),Fres、DLcoSB%_(pred)差异无统计学意义(P均>0.05)。肺气肿组内2亚组间临床严重程度比较差异有统计学意义(χ~2=4.17,P=0.041)。结论 COPD患者肺气肿空间分布影响肺功能及临床严重程度,下叶肺气肿为主患者肺功能相对较差,临床严重程度更重。

Objective To investigate the impact of spatial distribution of emphysema on pulmonary function and clinical severity in patients with chronic obstructive pulmonary disease（COPD）.Methods Chest MSCT was performed in 84 patients with COPD.The percentage of low attenuation areas were automatically calculated for each lobe with the COPD analysis software.The correlations between low-attenuation area percent（LAA%）of each lobe and the parameters of pulmonary function were analyzed.According to the pulmonary emphysema heterogeneity index,the patients were divided into non-emphysema group and emphysema group,and the latter were divided into the predominantly upper-lobe subgroup and the predominantly lower-lobe subgroup.The differences of pulmonary function parameters between the 2 groups and clinical severity between the 2 subgroups in emphysema group were compared.Results LAA% of each lobe was negatively correlated with single breath carbon monoxide diffusing capacity to predicted value ratio（DLcoSB%pred）.Except for the right middle lobe,LAA% of the remaining lobes were negatively correlated with forced expiratory volume in one second/forced vital capacity（FEV1/FVC）and FEV1%pred,while positively correlated with resonance frequency（Fres）.The differences of pulmonary function parameters between the 2 groups were statistically significant（all P〈0.05）.The differences of FEV1%pred and FEV1/FVC between the 2 subgroups in emphysema group were statistically significant（all P〈0.05）,and the differences of Fres and DLcoSB%pred between the 2 subgroups were not statistically significant（all P〈0.05）.The difference of clinical severity between the 2 subgroups was statistically significant（χ^2=4.17,P=0.041）.Conclusion The spatial distribution of pulmonary emphysema affects pulmonary function and clinical severity in COPD patients.The patients with the predominantly lower-lobe emphysema are relatively worse in lung function,and more serious in the clinical severity.