混合性通气障碍稳定期COPD患者肺弥散功能和肺毛细血管床容量的变化

目的探讨表现为混合性通气障碍的稳定期慢性阻塞性肺疾病（COPD）患者肺弥散功能和肺毛细血管床容量的变化情况及可能的病理生理影响因素。方法选择呈混合性通气障碍的稳定期COPD患者为COPD组,用体描箱测定其肺通气功能、肺容量和肺弥散功能,并设正常对照组。测定用力肺活量（FVC）、第1秒用力呼气容积（FEV1）、最大通气量（MVV）、肺活量（VC）、肺总量（TLC）、残气量（RV）、肺泡气量（VA）、一氧化碳弥散量（DLCO）、肺膜弥散量（DMCO）及肺毛细血管床容量（Vc）。采用SPSS 14.0统计软件数据作t检验进行统计分析,并就DLCO%pred、DMCO%pred及Vc%pred与各通气容量指标进行相关分析。结果 COPD组患者肺通气功能、肺容量及肺弥散功能指标与正常对照组比较差异均有统计学意义（P〈0.05或P〈0.01）。但COPD组患者的FVC、VC、VA及DMCO实测值占预计值百分比的平均值均在66%以上;TLC%pred平均值较正常上限稍高;而FEV1、MVV、DLCO及Vc实测值占预计值百分比的平均值异常偏低,在36%～44%之间;RV%pred平均值则异常偏高,达到188%。DLCO%pred、DMCO%pred及Vc%pred与FEV1%pred、FEV1/FVC、TLC%pred、RV%pred、RV/TLC及VA%pred等通气容量指标存在明显相关性。结论表现为混合性通气障碍的COPD患者多处于疾病中后期,肺毛细血管床严重受损,肺毛细血管床容量显著下降,以及严重的气体分布不均和通气/血流比例失调,其弥散功能的下降首先源自Vc的减低,由于Vc的减低从而导致DLCO、DMCO也随之呈不同程度的下降。

Changes of Pulmonary Diffusing Capacity and Pulmonary Capillary Blood Volume in Stable COPD Patients with Mixed Ventilation Dysfunction

Objective To investigate the changes of pulmonary diffusing capacity and pulmonary capillary blood volume in stable COPD patients with mixed ventilation dysfunction,and explore the possible pathophysiological factors.Methods 159 stable COPD patients with mixed ventilation dysfunction were recruited in the study and 36 normal subjects were recruited as control.The Belgium medisoft box5500 was used to determine the pulmonary ventilation function,lung capacity,and pulmonary diffusing capacity.The measured parameters included forced vital capacity(FVC),forced expiratory volume in one second(FEV1),maximal voluntary ventilation(MVV),vital capacity(VC),total lung capacity(TLC),residual volume(RV),minute volume of alveolar ventilation(VA),lung diffusing capacity for carbon monoxide(DLCO),pulmonary membrane diffusing capacity for carbon monoxide(DMCO),and pulmonary capillary blood volume(Vc).The above parameters were compared between the COPD patients and the normal subjects.The relationship was analyzed between DLCO%pred,DMCO%pred,Vc%pred and all the ventilation parameters.Results In stable COPD patients with mixed ventilation dysfunction,all parameters of pulmonary ventilation function,lung capacity,and pulmonary diffusing capacity were significantly different from the nor mal subjects(P<0.05 or P<0.01).FVC,VC,VA,and DMCO of the C OPD patients wer e about 66% of the calculated value or more.The average TLC%pred was a little hi gher than the normal.FEV1,MVV,DLCO and Vc were abnormally lower which were bet ween 36%~44%.The average RV%pred was 188% of the predicted value.Obvious correla tion could be detected between DLCO%pred,DMCO%pred,Vc%pred and FEV1%pred,FEV1 /FVC,TLC%pred,RV%pred,RV/TLC and VA%pred etc.Conclusions In COPD patients wi th mixed ventilation dysfunction,the pulmonary blood capillary is damaged serio usly which lead to a significant decrease of the capacity of pulmonary blood cap illary,as well as seriously air distribution disturbance and ventilation/bloods tream mismatch.The Vc decline may develope before the impairment of pulmonary di ffusing capacity which may contribute to the damaged of DLCO and DMCO.