呼出气一氧化氮在诊断哮喘中的作用
2011/01/27
摘要
原理：标准的哮喘诊断基于临床病史、气道阻塞的可逆性和支气管高反应性。呼出气一氧化氮水平（FeNO）为气道炎症的无创性标志物，有研究将其推荐作为哮喘的一个诊断工具。本文旨在建立FeNO在诊断哮喘时的临界值。
方法：114名连续就诊的、主诉有哮喘症状的成人患者（平均年龄：34±13岁）入选本研究，这些患者肺活量参数正常，而且支气管扩张剂检测阴性。所有患者在进行5次呼吸计数器检测之后都进行了乙酰甲胆碱激发试验。乙酰甲胆碱激发试验前即刻采用便携式仪器检测FeNO（NioxMino, Aerocrine AB, 瑞典）。评价FeNO检测的敏感性、特异性和诊断价值。
结果：114名患者中的35名（30.7％）诊断为哮喘。乙酰甲胆碱激发试验阳性与FeNO含量较高及基线状态下第一秒用力呼气体积（FEV1）较低相关。然而，导致FEV1下降20％的乙酰甲胆碱激发浓度（PC20）与FeNO水平无关。同时，构建FeNO水平的受试者工作特征曲线（曲线下面积[AUC]: 0.762; 95％CI：0.667-0.857；P<0.001）。诊断哮喘的敏感性和特异性达到最高时，FeNO的临界值为40 ppb。
结论：确诊为哮喘的患者其FeNO水平较高。对于本研究人群，将40 ppb作为FeNO的临界值在诊断哮喘时最为有效。检测FeNO有助于排除哮喘诊断，特别是在那些不适合或不能做乙酰甲胆碱激发试验的患者。
（苏楠 审校）
J Asthma. 2010 Aug 18. [Epub ahead of print]
Usefulness of Exhaled Nitric Oxide for Diagnosing Asthma.
Pedrosa M, Cancelliere N, Barranco P, López-Carrasco V, Quirce S.
Department of Allegy, University Hospital La Paz, Madrid, Spain.
Abstract
Rationale. A standard asthma diagnosis is made based on clinical history, reversibility of airway obstruction, and bronchial hyperresponsiveness. Fractional exhaled nitric oxide (FeNO) is a noninvasive airway inflammatory marker that has been suggested as a diagnostic tool for asthma. The aim of this study was to establish a FeNO cut-off value for asthma diagnosis.
Methods. One hundred and fourteen consecutive adult patients (mean age 34 +/- 13 years) reporting symptoms consistent with asthma, with normal spirometric parameters and a negative bronchodilator test, were included in the study. All underwent a methacholine challenge test following the five-breath dosimeter protocol. FeNO was measured with a portable device (NioxMino, Aerocrine AB, Sweden) just before the methacholine challenge. The sensitivity, specificity, and diagnostic performance of FeNO measurement were calculated.
Results. Thirty-five out of the 114 patients (30.7%) were diagnosed with asthma. A positive methacholine challenge was associated with higher FeNO levels and with lower forced expiratory volume in one second (FEV(1)) at baseline. No correlation was found between methacholine provocative concentration causing a decrease of 20% in FEV(1) (PC(20)) and FeNO levels. A receiver-operating characteristic curve was constructed for FeNO levels (area under the curve [AUC]: 0.762; 95% confidence interval [CI]: 0.667-0.857; p < .001). The FeNO cut-off point with maximal specificity and sensitivity for asthma diagnosis was 40 ppb.
Conclusions. Patients with confirmed asthma showed higher FeNO levels. A cut-off value of 40 ppb was calculated as the most efficient for asthma diagnosis in our population. The use of FeNO measurement may be a helpful tool to rule out a diagnosis of asthma, especially in patients in whom a methacholine challenge is not feasible or available.
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吸入皮质激素治疗的哮喘患者呼出气一氧化氮与哮喘负担的关系
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在城市的年轻哮喘患者中，对计算机设计的哮喘管理计划治疗无效的相关因素
