Petsky Helen L, Li Albert M, Au Chun T, Kynaston Jennifer A, Turner Catherine, Chang Anne B
Queensland Children's Medical Research Institute, Queensland University of Technology, Herston, Australia.
Department of Paediatrics, Prince of Wales Hospital, The Chinese University of Hong Kong, Shatin, Hong Kong.
Pediatr Pulmonol. 2015 Jun;50(6):535-43. doi: 10.1002/ppul.23064. Epub 2014 Jun 2.
While several randomized control trials (RCTs) have evaluated the use of fractional exhaled nitric oxide (FeNO) to improve asthma outcomes, none used FeNO cut-offs adjusted for atopy, a determinant of FeNO levels. In a dual center RCT, we assessed whether a treatment strategy based on FeNO levels, adjusted for atopy, reduces asthma exacerbations compared with the symptoms-based management (controls). Children with asthma from hospital clinics of two hospitals were randomly allocated to receive an a-priori determined treatment hierarchy based on symptoms or FeNO levels. There was a 2-week run-in period and they were then reviewed 10 times over 12-months. The primary outcome was the number of children with exacerbations over 12-months. Sixty-three children were randomized (FeNO = 31, controls = 32); 55 (86%) completed the study. Although we did achieve our planned sample size, significantly fewer children in the FeNO group (6 of 27) had an asthma exacerbation compared to controls (15 of 28), P = 0.021; number to treat for benefit = 4 (95% CI 3-24). There was no difference between groups for any secondary outcomes (quality of life, symptoms, FEV1 ). The final daily inhaled corticosteroids (ICS) dose was significantly (P = 0.037) higher in the FeNO group (median 400 µg, IQR 250-600) compared to the controls (200, IQR100-400). Taking atopy into account when using FeNO to tailor asthma medications is likely beneficial in reducing the number of children with severe exacerbations at the expense of increased ICS use. However, the strategy is unlikely beneficial for improving asthma control. A larger study is required to confirm or refute our findings.
虽然多项随机对照试验（RCT）评估了呼出气一氧化氮分数（FeNO）对改善哮喘预后的作用，但没有一项试验使用根据特应性（FeNO水平的一个决定因素）调整的FeNO临界值。在一项双中心RCT中，我们评估了一种根据特应性调整FeNO水平的治疗策略与基于症状的管理（对照组）相比，是否能减少哮喘发作。来自两家医院门诊的哮喘患儿被随机分配接受基于症状或FeNO水平的预先确定的治疗分级。有一个为期2周的导入期，然后在12个月内对他们进行10次复查。主要结局是12个月内哮喘发作的患儿数量。63名儿童被随机分组（FeNO组 = 31名，对照组 = 32名）；55名（86%）完成了研究。虽然我们达到了计划的样本量，但与对照组（28名中的15名）相比，FeNO组（27名中的6名）哮喘发作的患儿明显更少，P = 0.021；获益所需治疗人数 = 4（95%CI 3 - 24）。两组在任何次要结局（生活质量、症状、第一秒用力呼气容积）方面均无差异。FeNO组最终每日吸入糖皮质激素（ICS）剂量（中位数400μg，IQR 250 - 600）显著高于对照组（200，IQR100 - 400），P = 0.037。在使用FeNO调整哮喘药物时考虑特应性可能有助于减少重度发作患儿的数量，代价是ICS使用增加。然而，该策略不太可能对改善哮喘控制有益。需要进行更大规模的研究来证实或反驳我们的发现。
