呼出一氧化氮和哮喘的控制：一项在非选择性患者中进行的纵向调查
2008/04/30
以往的对照研究发现呼出一氧化氮(exhaled nitric oxide fraction，FeNO)监测能够提高哮喘的管理水平，但尚无研究调查FeNO在各种哮喘患者中的作用。为此，Michils等在一个普通临床机构——Erasme大学胸科医院过敏与哮喘门诊中，进行了一项为期4年的纵向调查，观察FeNO对即时哮喘控制状况的反映情况，并确定FeNO的截点和变化。
341例非选择性哮喘患者进行哮喘控制问卷（Asthma Control Questionnaire，ACT）调查和至少一次FeNO测定。分析范围包括所有研究对象和各个亚组：初次吸入激素组和既往吸入激素组（低剂量、中等剂量和高剂量组）。
研究发现，对于总人群，FeNO下降<40%或增长<30%分别可以排除哮喘控制最佳和恶化（阴性预测值NPV为79%和82%）。而对于不同亚组：在低剂量组中，FeNO下降40%则提示哮喘控制最佳（阳性预测值PPV为83%）；在初次激素吸入组中，FeNO>35 ppb则提示吸入激素显著改善了患者的哮喘控制(PPV 68%)。在大多数情况下，FEV1对于哮喘控制的评价没有用处。
根据研究，作者认为：在给定人群，FeNO与哮喘即时控制状况有明显的相关性；但在高剂量吸入激素组中，FeNO对哮喘控制的反应能力下降。FEV1对于评价哮喘控制并无更多价值。
（韩伟 青岛大学附属青岛市立医院东院呼吸科 266071 摘译）
(Eur Respir J 2008; 31(3): 539–546 )
A. Michils, S. Baldassarre and A. Van Muylem
Exhaled nitric oxide and asthma control: a longitudinal study in unselected patients.
Michils A, Baldassarre S, Van Muylem A.
Chest Dept, CUB Erasme, 808 Route de Lennik, B-1070 Brussels, Belgium. avmuylem@ulb.ac.be.
Controlled studies have shown that monitoring of the exhaled nitric oxide fraction (F(eNO)) improves asthma management. However, the studies seldom consider the full range of patients seen in clinical practise. In the present study, the ability of F(eNO) to reflect asthma control over time is investigated in a regular clinical setting, and meaningful F(eNO) cut-off points and changes are identified. Answers to the Asthma Control Questionnaire and F(eNO) were recorded at least once in 341 unselected asthma patients. The whole population and subgroups were considered, i.e. both inhaled corticosteroid (ICS)-naïve and low or high-to-medium (500 mug beclomethasone dipropionate equivalents.day(-1)) ICS-dose groups. An F(eNO) decrease <40% or increase <30% precludes asthma control optimisation or deterioration, respectively (negative predictive value 79 and 82%, respectively). In the present study’s low-dose group, a decrease >40% indicated asthma control optimisation (positive predictive value (PPV) 83%). In ICS-naïve patients, F(eNO) >35 ppb predicted asthma control improvement in response to ICS (PPV 68%). In most cases, forced expiratory volume in one second assessments were not useful. In conclusion, in a given patient, exhaled nitric oxide fraction was found to be significantly related to asthma control over time. The overall ability of exhaled nitric oxide fraction to reflect asthma control was reduced in patients using high doses of inhaled corticosteroids. Forced expiratory volume in one second had little additional value in assessing asthma control.
