呼出气一氧化氮水平预测哮喘患儿气道高反应性临床价值研究

摘要

Objective To evaluate the clinical value of fractional exhaled nitric oxide (FeNO) level in asthmatic children to predict bronchial hyperresponsiveness by analyzing the correlation between fraction of exhaled nitric oxide and bronchial provocation test.Methods One hundred and fourteen asthma outpatients of Shengjing Hospital were enrolled, FeNO levels, spirometry and bronchial provocation test were measured.Results In the bronchial provocation test,there were 33 positive and 81 negative cases.The positive group had a significantly higher FeNO levels than the negative ones(19.0 × 10-9 vs.16.0 × 10-9 ,p =0.000).By the ROC curve, the best FeNO cut-off value to predict bronchial hyperresponsiveness was 38.5 × 10-9 with high specificity (92.6％) but relatively low sensitivity (36.4％).There was no relationship between methacholine provocative dose causing a 20％ fall in FEV1 (PD20-FEV1) and the level of FeNO.Conclusion FeNO level has important predicting value for bronchial hyperreactivity in children with asthma.The level of FeNO ＞ 38.5 × 10-9 has high predictive value in asthmatic children with bronchial hyperreactivity.%目的 分析哮喘患儿呼出气一氧化氮(fractional exhaled nitric oxide,FeNO)水平与支气管激发试验结果的相关性,探讨应用FeNO预测哮喘患儿气道高反应性.方法 选取于中国医科大学附属盛京医院儿童哮喘门诊就诊的114例初诊哮喘患儿,进行呼出气一氧化氮、肺功能和乙酰甲胆碱为激发剂的支气管激发试验检查.为明确FeNO是否能对支气管激发试验结果有预测作用,绘制FeNO水平与支气管激发试验间的ROC曲线.结果 支气管激发试验阳性组33例,阴性组81例,支气管激发试验阳性组的FeNO值为19.0×10-9(13.5×10-9～49.0×10-9),阴性组的FeNO值为16.0×10-9(12.0×10-9～24.0×10-9),两组间差异有统计学意义(P=0.000);由ROC曲线,得出FeNO预测支气管激发试验结果阳性的界值点(cut off point)为38.5×10-9,其检验敏感性为36.4％,特异性为92.6％.FeNO值与FEV1下降20％时吸入的乙酰甲胆碱累积计量(PD20-FEV1)之间不存在剂量相关性.结论 FeNO水平对支气管激发试验结果有一定的预测作用.当FeNO水平＞38.5 ×10-9时可以预测支气管激发试验结果为阳性的准确性较高,提示患儿存在气道高反应性.