哮喘联盟

    背景:有关呼出气一氧化氮（NO）测定在哮喘管理中临床应用意义的初步研究仅得出了一些模棱两可的证据。本文试图评价在根据哮喘指南治疗内陆城市青少年和年轻成人哮喘患者时，同时测定气道炎症的生物指标呼出气NO是否可提高哮喘治疗的有效性。
    方法：在美国的10个中心进行了随机双盲平行对照研究。共筛选了780名内陆城市持续哮喘患者，年龄在12～20岁。所有患者在3周的导入期内接收了标准方案治疗。546名在导入期内坚持治疗的患者纳入研究，随机分为两组，一组接受根据国家哮喘教育和预防计划指南（NAEPP）推荐的标准方案治疗，另一组的标准治疗方案则根据呼出气NO测定结果进行调整。主要观察指标为有哮喘症状天数。根据意向治疗分析结果。
    结果：在为期46周的治疗中，两组间有哮喘症状天数的均数没有显著差异 (NO指导组为1.93 [95% CI 1.74 to 2.11] ，对照组为 1.89 [1.71 to 2.07] ；差值0.04 [-0.22 to 0.29], p=0.780)。两组间其他症状、肺功能及哮喘急性发作次数也没有显著差异。NO指导组患者吸入激素量高于对照组(差值为 119 mug/天, 95% CI 49 to 189, p=0.001) 。两组间不良事件发生率没有显著差异。
    结论：对大多数受试者传统哮喘管理方式就可以良好地控制症状。测定呼出气NO作为额外的哮喘控制指标导致吸入激素量增加，却不能进一步改善哮喘症状控制。

（马艳良 北京大学人民医院呼吸科 100044 摘译）
（Lancet. 2008 Sep 20;372(9643):1065-1072）

Management of asthma based on exhaled nitric oxide in addition to guideline-based treatment for inner-city adolescents and young adults: a randomised controlled trial.

Szefler SJ, Mitchell H, Sorkness CA, Gergen PJ, O’Connor GT, Morgan WJ, Kattan M, Pongracic JA, Teach SJ, Bloomberg GR, Eggleston PA, Gruchalla RS, Kercsmar CM, Liu AH, Wildfire JJ, Curry MD, Busse WW.
Lancet. 2008 Sep 20;372(9643):1065-72.

BACKGROUND: Preliminary evidence is equivocal about the role of exhaled nitric oxide (NO) in clinical asthma management. We aimed to assess whether measurement of exhaled NO, as a biomarker of airway inflammation, could increase the effectiveness of asthma treatment, when used as an adjunct to clinical care based on asthma guidelines for inner-city adolescents and young adults.
METHODS: We did a randomised, double-blind, parallel-group trial at ten centres in the USA. We screened 780 inner-city patients, aged 12-20 years, who had persistent asthma. All patients completed a run-in period of 3 weeks on a regimen based on standard treatment. 546 eligible participants who adhered to treatment during this run-in period were then randomly assigned to 46 weeks of either standard treatment, based on the guidelines of the National Asthma Education and Prevention Program (NAEPP), or standard treatment modified on the basis of measurements of fraction of exhaled NO. The primary outcome was the number of days with asthma symptoms. We analysed patients on an intention-to-treat basis. This trial is registered with clinicaltrials.gov, number NCT00114413.
FINDINGS: During the 46-week treatment period, the mean number of days with asthma symptoms did not differ between the treatment groups (1.93 [95% CI 1.74 to 2.11] in the NO monitoring group vs 1.89 [1.71 to 2.07] in the control group; difference 0.04 [-0.22 to 0.29], p=0.780). Other symptoms, pulmonary function, and asthma exacerbations did not differ between groups. Patients in the NO monitoring group received higher doses of inhaled corticosteroids (difference 119 mug per day, 95% CI 49 to 189, p=0.001) than controls. Adverse events did not differ between treatment groups (p>0.1 for all adverse events). 
INTERPRETATION: Conventional asthma management resulted in good control of symptoms in most participants. The addition of fraction of exhaled NO as an indicator of control of asthma resulted in higher doses of inhaled corticosteroids, without clinically important improvements in symptomatic asthma control.