FEV3/FVC单独下降在判断早期肺部疾病中的应用潜能

摘要

目的 探讨第3秒用力呼气容积/用力肺活量(FEV3/FVC)在判断早期气道阻塞、轻度气体陷闭等早期肺部疾病中的应用潜能.方法 收集2014年1月至2017年10月于本院肺功能室行肺功能检查者共288例(排除限制性通气功能障碍者),将288例患者分为三组.A组:FEV3/FVC及第1秒用力呼气容积/用力肺活量(FEV1/FVC)均正常;B组:FEV3/FVC单独下降;C组:FEV1/FVC下降.对三组一般资料及肺功能指标进行比较.结果 与A组比较,B组有较低的FEV1％、肺一氧化碳弥散量(DLCO％),有较高的肺总量(TLC％)、残气容积(RV％)、RV/TLC％.与B组比较,C组的FEV1％、DLCO％的降低更明显,且有更高的TLC％、RV％、RV/TLC％改变.三组小气道功能指标两两比较差异均有统计学意义(P≤0.01).FEV3/FVC与用力呼气75％肺活量(余25％肺活量)的瞬间流量(MEF25％)、用力呼气50％肺活量(余50％肺活量)的瞬间流量(MEF5o％)、最大呼气中期流量(MMEF％)呈正相关(r=0.610、0.613、0.608,P≤0.01).以FEV3/FVC作为判定气道阻塞的指标,其灵敏度为98.5％,特异度为45.7％,阳性预测值35.5％,阴性预测值99％.结论 FEV3/FVC单独下降是轻度气道阻塞、早期气体陷闭,弥散障碍等早期肺部疾病的指征.%Objective To explore the application potential of forced expiratory volume in three second/forced vital capacity (FEV3/FVC) in early lung diseases,such as early airway obstruction and mild gas trap.Methods A total of 288 patients (excluding those with restrictive ventilation dysfunction) who underwent pulmonary function examination in the pulmonary function room of our hospital from January 2014 to October 2017 were collected.288 patients were divided into three groups.Group A:FEV3/FVC and forced expiratory volume in one second/forced vital capacity (FEV1/FVC) were normal;Group B:FEV3/FVC decreased alone;Group C:FEV1/FVC decreased.The general data and pulmonary function indexes of the three groups were compared.Results Compared with group A,group B had lower FEV1 ％ and diffusion capacity for carbon monoxide of the lung (DLCO％),but higher total lung capacity (TLC％),residual volume (RV％) and RV/TLC.Compared with group B,group C had higher TLC ％,RV％,RV/TLC％,while FEV1％,DLCO％ reduce more remarkably.There were significant differences in the three groups of small airway function (P ≤ 0.01).FEV3/FVC was positively correlated with max expiratory at 50％ FVC (MEF50％),max expiratory at 75％ FVC (MEF25％) and maximal mid expiratory flow (MMEF％).The correlation coefficients were respectively 0.613,0.610,0.608 (P ≤0.01).When FEV3/FVC serves as an indicator to determine airway obstruction,the specificity of it is 45.7％,sensitivity 98.5％,and negative predictive value 99％,positive predictive value 35.5％.Conclusions FEV3/FVC individual decline is the indication of early lung diseases such as mild airway obstruction,mild gas trap and diffuse disorder.