呼出气一氧化氮联合小气道功能检查对小儿咳嗽变异性哮喘与感染后咳嗽引起的慢性咳嗽的鉴别诊断价值

Differential diagnostic value of fractional exhaled nitric oxide combined with small airway function tests in children with chronic cough caused by cough variant asthma and post-infectious cough

目的探讨呼出气一氧化氮(FeNO)联合小气道功能检查对小儿咳嗽变异性哮喘(CVA)与感染后咳嗽引起的慢性咳嗽的鉴别诊断价值。方法选择2018年5月至2021年7月扬州大学附属医院收治的89例慢性咳嗽患儿为研究对象,根据病因不同分为CVA组(34例)与感染后咳嗽组(55例)。比较两组入院1 d的FeNO浓度与小气道功能[第一秒用力呼气容积(FEV_(1))、用力呼出50%肺活量时的瞬间流量(FEF_(50))、用力肺活量(FVC)、最大呼气中期流量75/25(MMEF_(75/25))],分析CVA引起慢性咳嗽的影响因素。结果两组年龄、性别、咳嗽时间、淋巴细胞分数、中性粒细胞分数、日间咳嗽症状积分、夜间咳嗽症状积分比较,差异无统计学意义(P>0.05)。CVA组FeNO浓度高于感染后咳嗽组,FEF_(50)、MMEF_(75/25)低于感染后咳嗽组,差异有统计学意义(P<0.05);两组FEV_(1)、FVC比较,差异无统计学意义(P>0.05)。FeNO浓度、MMEF_(75/25)、FEF_(50)为CVA引起的慢性咳嗽的影响因素(OR>1,P<0.05)。FeNO联合FEF_(50)、MMEF_(75/25)诊断小儿CVA与感染后咳嗽引起的慢性咳嗽的曲线下面积为0.894,灵敏度为88.24%,特异度为87.27%。结论FeNO、MMEF_(75/25)、FEF_(50)在鉴别诊断CVA引起的慢性咳嗽中具有一定的价值。

Objective To explore the differential diagnostic value of fractional exhaled nitric oxide(FeNO)combined with small airway function tests in children with chronic cough caused by cough variant asthma(CVA)and post-infectious cough.Methods A total of 89 children with chronic cough who were admitted to the Affiliated Hospital of Yangzhou University from May 2018 to July 2021 were selected as study object,they were divided into CVA group(34 cases)and post-infection cough group(55 cases)according to different etiologies.The FeNO concentration and small airway function(forced expiratory volume in the first second[FEV_(1)],forced expiratory flow at 50%vital capacity[FEF_(50)],forced vital capacity[FVC],maximum mid-expiratory flow 75/25[MMEF_(75/25)])of two groups were compared on the 1st day of admission.The influencing factors of CVA-induced chronic cough were analyzed.Results There were no significant difference in age,sex,cough time,lymphocyte fraction,neutrophil fraction,daytime cough symptom score,and nighttime cough symptom score between two groups(P>0.05).FeNO concentration in CVA group was higher than that in post-infection cough group,FEF_(50)and MMEF_(75/25)were lower than those in post-infection cough group,and the differences were statistically significant(P<0.05);there were no significant differences in FEV_(1)and FVC between two groups(P>0.05).FeNO concentration,MMEF_(75/25),and FEF_(50)were the influencing factors of CVA-induced chronic cough(OR>1,P<0.05).The area under the curve of FeNO combined with FEF_(50)and MMEF_(75/25)was 0.894,the sensitivity was 88.24%,and the specificity was 87.27%.Conclusion FeNO,MMEF_(75/25),and FEF_(50)have certain value in the differential diagnosis of CVA-induced chronic cough.