慢性阻塞性肺疾病诊断中总气道阻力测定的价值探讨

Airway resistance at 5 Hz： an alternative parameter for diagnosis of chronic obstructive pulmonary disease

目的探讨脉冲振荡法中总气道阻力（5Hz时气道阻力，R5）在慢性阻塞性肺疾病（COPD）诊断和严重程度分级中的应用价值，并且对与第1秒用力呼气容积／用力肺活量（FEV1／FVC）〈70％和FEV1 pred％〈80％对应的R5％诊断阈值进行探讨。方法应用德国耶格公司生产的Master Screen肺功能仪分别进行常规肺功能和脉冲振荡法测定，选用FEV1、R5实测值，FEV1、R5实测值／预计值百分比，FEV1/FVC百分比等作为分析指标。分析各指标间相关关系，以FEV1／FVC〈70％作为判断COPD患者有无气流受限的“金标准”．以FEVtpred％〈80％作为判断COPD患者严重程度分级的“金标准”以四格表分析决定相应的R5％的诊断灵敏度、特异度和约登指数。结果107例受试者中FEV1／FVC〈70％并符合慢性阻塞性肺疾病诊治指南标准为55例。他们的R5和R5实测值占预计值％明显升高。R5与FEV1呈显著负相关，R5占预计值％与FEV1和FEV1／FVC占预计值％也呈显著负相关。以FEV1／FVC〈70％作为诊断气流受限的“金标准”，分别以R5实测值／预计值〉150％或〉130％为标准的诊断灵敏度为73％、89％；特异度为77％、71％；约登指数为0．5、0．53。以FEV1〈80％作为判断COPD患者严重程度分级的“金标准”，分别以R5实测值／预计值〉150％或〉130％为标准的诊断灵敏度为65％、73％；特异度为88％、82％；约登指数为0．53、0．55。结论在COPD诊断中，以R5实测值／预计值〉130％为标准优于〉150％；合适的诊断阈值尚有待于将来进一步探讨。

Objective To determine the efficacy of R5 in the diagnosis of COPD and the fixed cut off point of R5% which can be used as an alternative for the FEV1 ：FVC〈70% and FEV1pred% （80%. Methods Spirometry and IOS measurements （Jaeger MasterScreen, Germany） were performed in 107 participants. FEV1 , FVC, FEV1/FVC, and R5 were analyzed. Correlation between FEV1, FVC, FEV1/FVC and R5 were studied. FEV1/FVC〈70% and FEV1 〈80% was used as the＂gold standard ＂to determine the sensitivity and specificity of R5. Results R5 and R5% significant increased in COPD group （55 participants）. There was significant negative correlation between FEV1 , FVC, FEV1/FVC and R5. Use FEV1/FVC〈70% as the＂gold standard＂ , sensitivity of R5%〉150% or 〉130% was 73% ,89%;specificity was 77%,71%; Youden index was 0.5,0.53 respectively. Use FEV1 〈80% as the＂gold standard＂, sensitivity of R5%150% or 〉130%was 65% ,73% ;specificity was 88% ,82%;Youden index was 0.53, 0.55 respectively. Conclusions In the diagnosis of COPD, R5% 〉 130% is superior to 〉 150%. Further researches need to establish the diagnosis criteria.