呼出气一氧化氮在儿童慢性咳嗽病因诊断中的应用价值

Application value of fractional exhaled nitric oxide in etiological diagnosis of chronic cough in children

目的探讨呼出气一氧化氮(FeNO)在儿童慢性咳嗽病因诊断中的应用价值。方法选择2020年7月至2021年7月河北省定州市人民医院就诊的200例慢性咳嗽患儿为研究对象。分析患儿慢性咳嗽病因;比较不同病因患儿FeNO、肺功能、诱导痰嗜酸粒细胞计数;分析FeNO对不同病因慢性咳嗽患儿的诊断价值。结果200例慢性咳嗽患儿中确定病因198例,病因不明2例;单一病因172例,二重病因21例,其他原因5例。儿童慢性咳嗽病因前五位依次为上气道咳嗽综合征(UACS),咳嗽变异性哮喘(CVA),感染后咳嗽(PIC),嗜酸性粒细胞性支气管炎(EB),CVA+UACS。不同病因患儿FeNO、使第1秒用力呼气容积下降20%所需激发药物的累积量、诱导痰嗜酸性粒细胞百分比比较,差异有统计学意义(P<0.05);不同病因患儿第1秒用力呼气容积、第1秒用力呼气容积/用力肺活量比较,差异无统计学意义(P>0.05)。FeNO诊断PIC的曲线下面积(AUC)值为0.765[95%CI(0.651~0.878)],最佳截断值19.0 ppb,灵敏度为80.0%,特异度为63.8%,约登指数为0.44。FeNO诊断UACS的AUC值为0.835[95%CI(0.760~0.909)],最佳截断值15.5 ppb,灵敏度为82.0%,特异度为73.2%,约登指数为0.55。FeNO诊断CVA的AUC值为0.947[95%CI(0.898~0.996)],最佳截断值24.5 ppb,灵敏度为86.0%,特异度为88.0%,约登指数为0.74。FeNO诊断EB的AUC值为0.814[95%CI(0.693~0.935)],最佳截断值19.5 ppb,灵敏度为81.0%,特异度为83.0%,约登指数为0.64。FeNO诊断CVA+UACS的AUC值为0.916[95%CI(0.817~1.000)],最佳截断值18.5 ppb,灵敏度为80.0%,特异度为73.3%,约登指数为0.53。结论FeNO作为一种气道炎症标志物,可作为评估气道炎症的方法,可以把嗜酸粒细胞相关性气道炎症疾病从慢性咳嗽的其他病因中识别出来。FeNO可作为儿童慢性咳嗽的重要诊断依据。

Objective To explore the application value of fractional exhaled nitric oxide(FeNO)in etiological diagnosis of chronic cough in children.Methods A total of 200 children with chronic cough treated in Dingzhou People’s Hospital of Hebei Province from July 2020 to July 2021 were selected as the study objects.The etiological of chronic cough was analyzed;FeNO,lung function,and eosinophilic granulocyte count in induced sputum were compared;the diagnostic value of FeNO in children with chronic cough of different etiology was analyzed.Results Among 200 children with chronic cough,198 cases were identified and 2 cases were unknown.There were 172 cases of single cause and 21 cases of double cause,5 cases of other reasons.The top five etiologies of chronic cough in children were upper airway cough syndrome(UACS),cough variant asthma(CVA),postinfectious cough(PIC),eosinophilic bronchitis(EB),and CVA+UACS.There were statistically significant differences in FeNO,the cumulative amount of provocative medication required to reduce forced expiratory volume in one second by 20%,and the percentage of eosinophils in induced sputum among children with different etiologies(P<0.05);there were no significant differences in forced expiratory volume in one second and forced expiratory volume in one second/forced vital capacity of children with different etiologies(P>0.05).The area under the curve(AUC)value of FeNO diagnosis PIC was 0.765[95%CI(0.651-0.878)],the optimal cut-off value was 19.0 ppb,the sensitivity was 80.0%,the specificity was 63.8%,and the Yoden index was 0.44.The AUC value for FeNO diagnosis of UACS was 0.835[95%CI(0.760-0.909)],the optimal cut-off value was 15.5 ppb,the sensitivity was 82.0%,the specificity was 73.2%,and the Yoden index was 0.55.The AUC value for FeNO diagnosis of CVA was 0.947[95%CI(0.898-0.996)],the optimal cut-off value was 24.5 ppb,the sensitivity was 86.0%,the specificity was 88.0%,and the Yoden index was 0.74.The AUC value of FeNO diagnosis of EB was 0.814[95%CI(0.693-0.935)],the optimal cut-off value was 19.5 ppb,the sensitivity was 81.0%,the specificity was 83.0%,and the Yoden index was 0.64.The AUC value for FeNO diagnosis of CVA+UACS was 0.916[95%CI(0.817-1.000)],the optimal cut-off value was 18.5 ppb,the sensitivity was 80.0%,the specificity was 73.3%,and the Yoden index was 0.53.Conclusion FeNO,as a marker of airway inflammation,can be used as a method to evaluate airway inflammation,and it can be used to identify eosinophile-associated airway inflammatory diseases from other causes of chronic cough.FeNO can be used as an important diagnostic basis for chronic cough in children.