常规肺功能与脉冲振荡肺功能评价COPD患者气道阻塞程度一致性的研究

Study on the consistency between pulmonary function test and impulse oscillometry system in evaluation of severity of chronic obstructive pulmonary disease

目的研究常规肺功能测试(pulmonary function test, PFT)与脉冲振荡肺功能(impulse oscillometry system, IOS)评价慢性阻塞性肺疾病(chronic obstructive pulmonary disease, COPD)气道阻塞严重程度的一致性。方法对2016年4月-2017年4月随访的116例稳定期COPD患者(男性103例、女性13例)依次进行IOS检测和PFT检测,应用统计学分析软件对IOS和PFT参数行一致性与相关性分析。结果 116例受试者中,仅38例(32.8%)受试者气道阻塞严重程度分级结果一致,分级一致性存在较大差异(P<0.05);在78例严重程度不同的受试者中,52例IOS分级重于PFT分级。将52例IOS分级较重的患者与其余患者对比分析发现,这部分患者的PFT参数中,用力肺活量占预计值百分比(forced vital capacity, FVC%pred)、第1秒用力呼气容积占预计值百分比(forced vital capacity in one second, FEV1%pred)、第1秒用力呼气容积与用力肺活量之比(ratio of forced expiratory volume in one second to forced vital capacity, FEV1/FVC)较对照组均有升高(P<0.05);而IOS参数中振荡频率为5Hz时的黏性阻力(respiratory resistance at 5Hz, R5)、振荡频率为20Hz时的黏性阻力(respiratory resistance at 20Hz, R20)、振荡频率为5Hz和20Hz时的黏性阻力差值(difference between respiratory resistance at 5Hz and 20Hz, R5-R20)、共振频率(resonant frequency, Fres)较对照组均升高(P<0.05);IOS与PFT各参数相关性分析中,IOS参数:低频电抗面积(reactance area, AX)、R5-R20、ΔR5-R20、Fres、R5与PFT参数:FEV1%pred、FVC%pred、FEV1/FVC、第3秒用力呼气容积与用力肺活量之比(ratio of forced expiratory volume in three second to forced vital capacity, FEV3/FVC)、50%肺活量时最大呼吸流速(maximal expiratory flow rate at 50%of vital capacity, FEF50)、75%肺活量时最大呼吸流速(maximal expiratory flow rate at 75%of vital capacity, FEF75)呈负相关(P<0.01),与残气与肺总量之比(ratio of residual volume to total lung volume, RV/TLC)呈正相关(P<0.01)。结论 IOS与PFT对COPD气道阻塞严重程度评价存在差异,在早中期气道阻塞患者中,IOS损害程度级别显著高于PFT,IOS在评价小气道功能障碍时敏感性可能高于PFT,在临床应用中将二者相互结合可能可以更好地评价气道功能障碍。

Objective To study the consistency between pulmonary function test(PFT) and impulse oscillometry system(IOS) in evaluation of the severity of chronic obstructive pulmonary disease(COPD). Methods IOS and PFT were performed in 116 COPD patients(103 men and 13 women). During the examination the IOS was performed first to avoid the effect of forced expiratory. Results Among 116 subjects only 38(32.8%) had the same grades of severity of airway obstruction. There were significant differences between two methods(P<0.05). Among 78 subjects with different severity, 52 had higher IOS grades than PFT grades. In PFT parameters 52 patients with severe IOS grading had higher FVC%pred, FEV1%pred and FEV1/FVC than the control group(P<0.05). In IOS parameters, the R5, R20 and R5/R20 Fres were higher than those of control group(P< 0.05). The parameters of ISO 5 Hz and 20 Hz R5-R20, ΔR5-R20, resonant frequency Fres, respiratory resistance at 5 Hz R5 were negatively correlated with parameters of PFT forced vital capacity(FVC%pred), forced vital capacity in one second(FEV1%pred), ratio of forced expiratory volume in one second to forced vital capacity(FEV1/FVC), ratio of forced expiratory volume in three second to forced vital capacity(FEV3/FVC), maximal expiratory flow rate at 50% of vital capacity(FEF50) and maximal expiratory flow rate at 75% of vital capacity(FEF75)(all P<0.01);while were positively correlated with RV/TLC in PFT(P<0.01). Conclusion The IOS and PFT have significant differences in evaluating airway obstruction degree of COPD patients. The patients with moderate airway obstruction had a milder impairment classification with the IOS than with the PFT. IOS may be more sensitive than PFT in diagnosing small airway resistance. In order to better evaluate COPD, two methods should be integrated in clinical application.