92例咳嗽变异性哮喘患者的呼出气一氧化氮浓度与气流阻塞的相关研究

Association between exhaled nitric oxide and airflow obstruction in patients with cough variant asthma

目的:观察咳嗽变异性哮喘(cough variant asthma,CVA)患者的呼出气一氧化氮浓度(F E NO)变化及其与气流阻塞间的相关性。方法:2012年7月至2013年6月经支气管激发试验确诊的92例CVA成人患者,分别行常规肺功能、脉冲振荡肺功能和F E NO检测。结果:92例CVA患者中44例的F E NO>50 ppb,34例的F E NO为25~50 ppb,仅14例F E NO<25 ppb。3组患者均无显著的气流阻塞,但均有轻度外周小气道障碍。脉冲振荡肺功能测试中,所有患者的呼吸总阻抗和共振频率均略有增高,同时反映外周气道阻力的外周气道阻抗及5 Hz、20 Hz粘性阻力差值(R5-R20)也出现显著增高。结论:F E NO与气道高反应性密切相关,CVA患者的F E NO水平普遍增高,且同时合并外周气道气流阻塞。F E NO检测有助于CVA的临床诊断。

Objective： To observe the changes of fractional exhaled nitric oxide （FENO） in patients with cough variant asthma （CVA） and correlation of FENO with airflow obstruction. Methods： Ninety-two patients with bronchial provocation test confirmed CVA from July 2012 to June 2013 were enrolled. Routine lung function tests, impulse oscillometry （lOS） lung function test, and FENO test using nitric oxide analyzer （Nano Coulomb, Sunvou Biotech, Wuxi, China） were performed. Results Forty-four patients had high level of FENO （〉50 ppb）, 34 patients had FENO level of 25- 50 ppb, only 14 patients had a F^NO value below 25 ppb. No significant airflow obstruction was found, but low FEF~_75 （%） predicted value was seen in all CVA patients. IOS parameters such as total respiratory impedance （Zrs）, resonant frequency （Fres） were increased slightly, and peripheral resistance （Rp） and R5-R20 were increased significantly. Conclusions： There is a close association between exhaled nitric oxide and bronchial hyper-responsiveness （BHR）. High FENO value and peripheral airflow obstruction are seen in CVA patients, and FENO test could be used as a diagnostic tool for CVA.