哮喘儿童连续性监测呼出气一氧化氮水平的临床意义

Clinical value of continuous monitoring of fraction of exhaled nitric oxide in childhood asthma

摘要:

目的：探讨哮喘儿童呼出气一氧化氮水平（FeNO）的变化特点及临床意义。方法：20例在哮喘专科就诊的的轻-中度哮喘患儿，分別在治疗后8周、16周、24周、32周、40周进行随访。随访时记录哮喘症状，检测肺功能及FeNO。结果：治疗8周后FeNO均值迅速下降，后逐渐缓慢下降。与治疗前比较，治疗8周、16周、24周、32周及40周后的FeNO均值显著降低，差异有统计学意义（P＜0.01）。急性发作时FeNO水平较发作前明显增高，待病情缓解后FeNO水平随之快速下降。相关性分析显示FeNO与第1秒用力呼气容积（FEV1）呈负相关(r=-0.193，P＜0.05)。受试者工作曲线提示当FeNO为35.5 ppb时，FeNO预测哮喘未控制的敏感性为87.9%，特异性是80%；FeNO为20.5 ppb时，敏感性为97%，特异性为27.1%。结论：动态监测FeNO可以用于判断哮喘儿童气道炎症的控制水平；当FeNO值小于20.5 ppb时气道炎症可能控制良好，而当大于35.5 ppb时气道炎症很有可能处于未控制状态；FeNO的急性增高提示患儿有急性发作的可能。

Abstract:

OBJECTIVE: To investigate changes in the fraction of exhaled nitric oxide (FeNO) in childhood asthma, and to evaluate the clinical value of continuous monitoring of FeNO. METHODS: Twenty children with mild to moderate asthma were enrolled from the special outpatient clinic for asthma. Follow-up was performed at 8, 16, 24, 32 and 40 weeks after treatment. At each follow-up, asthmatic symptoms were recorded, pulmonary function was evaluated and FeNO was measured. RESULTS: The mean FeNO decreased rapidly 8 weeks after treatment and slowly afterwards. It decreased significantly 8,16,24 and 40 weeks after treatment (P<0.01). It increased significantly during acute attacks of asthma and decreased rapidly during periods of remission. There was significant negative correlation between FeNO and forced expiratory volume in one second (r =-0.193，P<0.05). The receiver operating characteristic curve of FeNO showed that FeNO had a sensitivity of 87.9% and a specificity of 80% for uncontrolled asthma when FeNO was 35.5 ppb, and that it had a sensitivity of 97% and a specificity of 27.1% when FeNO was 20.5 ppb. CONCLUSIONS: monitoring of FeNO can be used to evaluate the control level of airway inflammation in childhood asthma. When FeNO is less than 20.5 ppb, airway inflammation may be well controlled. When FeNO is more than 35.5 ppb, airway inflammation may be out of control. A sharp increase in FeNO suggests the possibility of acute asthma attack in children.