以胸闷或长叹气为主诉的不典型哮喘儿童肺功能和呼出气一氧化氮特点分析

目的 分析以胸闷或长叹气为主诉的不典型哮喘儿童的肺功能和呼出气一氧化氮(fractional exhaled nitric oxide,FeNO)特点,并探讨FeNO在该类型哮喘患儿中的诊断价值.方法 选取2012年1月至2015年6月期间于我院儿童哮喘门诊确诊的以胸闷或长叹气为主诉的不典型哮喘儿童79例为研究对象(不典型哮喘组).该组患儿于初诊时均接受了肺功能检查、FeNO检测、血清总IgE和血清特异性IgE水平检测,且肺功能检测均存在支气管激发试验或支气管舒张试验阳性.同期选取我院完成FeNO检测的健康儿童100例作为对照组.分析不典型哮喘组初诊时肺功能特点和FeNO水平.采用受试者工作特征曲线(ROC)分析FeNO对于不典型哮喘儿童的诊断价值.结果 不典型哮喘组肺功能指标FEF50、FEF75、MMEF异常率分别为27％、43％、33％.FEV1％下降20％时吸入的乙酰甲胆碱累积剂量(PD20-FEV1)为0.41 (0.19～0.67)mg,该指标与MMEF呈显著正相关(r=0.301,P=0.007).不典型哮喘组Fe-NO值为13.0×10-9 (7.0×10-9～24.0×10-9),高于对照组且两者间存在统计学差异(P＜0.05).其Fe-NO值与总IgE水平呈显著正相关(r =0.672,P=0.001),与FEV1/FVC％、FEV1％ pred及PD20-FEV1均不存在相关性(P＞0.05).根据不典型哮喘儿童和健康儿童的FeNO值绘制ROC曲线,曲线下面积为0.60.结论 以胸闷或长叹气为主诉的哮喘儿童肺功能特点以小气道功能受损为主,其中MMEF下降明显者,其气道高反应更显著,FeNO检测对不典型哮喘诊断价值有限.

Characteristics of lung function and exhaled nitric oxide in atypical asthma children with chest tightness or sighing breath as sole manifestation

Objective To study the characteristics of pulmonary function in atypical asthmatic children with chest tightness or sighing breath as the sole presenting manifestation,and explore the diagnostic values of fractional exhaled nitric oxide (FeNO) for the atypical asthma.Methods Seventy-nine atypical asthmatic children with chest tightness as the sole presenting manifestation during January 2012 to June 2015 were selected as subjects.All of the subjects performed spirometry,FeNO measurement,total serum IgE and specific IgE determination on their first visit,and with either positive bronchial provocation test or positive bronchial dilation test.As well as 100 healthy children who perfomred FeNO measurement were selected as control group during the same period.The pulmonary function data and FeNO values were analyzed in children who were finally confirmed as atypical asthma.Results In atypical asthma children,the abnormal rate of forced expiratory flow 50％,75％ (FEF50,FEF75) and maximum mid-expiratory flow (MMEF) were 27％,43％ and 33％.Methacholine provocation dose causing a 20％ fall in FEV1 (PD20-FEV1) were 0.41 (0.19 ～0.67)mg and were positively related with MMEF(r =0.301,P =0.007).FeNO concentration in atypical asthma patients were 13.0 × 10-9 (7.0 ×10-9 ～24.0 × 10-9),higher than that in control group(P ＜0.05).Significant correlations were found between FeNO and total serum IgE (r =0.672,P =0.001).No correlations were found between FeNO and FEV1 (P ＞0.05),between FeNO and FEV1/FVC％ (P ＞0.05) or between FeNO and PD20-FEV1 (P ＞0.05).The diagnostic values of FeNO for the atypical asthma were analyzed using the receiver operating characteristic curve,the area under the curve was 0.600.Conclusion The characteristics of pulmonary function in atypical asthma are hypofunction mainly in small airway and patients with lower MMEF had higher airway hyperresponsiveness.The diagnostic values of FeNO in atypical asthma are limited.