Department of Paediatrics, Oslo University Hospital, Oslo, Norway.
Acta Paediatr. 2010 Mar;99(3):404-10. doi: 10.1111/j.1651-2227.2009.01625.x. Epub 2009 Dec 22.
Measures of lung function (usually FEV(1) <80% predicted) are used to classify asthma severity in both adults and children, despite evidence that lung function impairment is less pronounced in the paediatric asthma population. The present study assesses the relevance of lung function measurements as discriminators of severe childhood asthma.
Fifty-one school-aged children with problematic severe asthma, 37 mild-to-moderate asthmatics and 29 healthy controls underwent a comprehensive clinical work-up. Problematic severe asthma was defined in patients exhibiting poor asthma control despite high-dose inhaled corticosteroid treatment and at least one other asthma controller drug. Mild-to-moderate asthmatic children used low-dose inhaled steroids and reported minimal asthma symptoms.
Baseline FEV(1) values were significantly reduced in children with problematic severe asthma, yet FEV(1) <80% predicted showed a low sensitivity (41%) for discriminating severe vs. mild-to-moderate asthma. Receiver-operated characteristic analysis estimated the optimal cut-off of FEV(1) to be 90% predicted in this population (sensitivity 61%, specificity 83%). Baseline FEV(1)/FVC and FEF(25-75) values were not superior to FEV(1) in discriminating problematic severe asthma, and neither exhaled nitric oxide levels nor bronchial hyperresponsiveness differentiated between the two asthmatic study populations.
Spirometric measurements are insensitive discriminators of problematic severe asthma in childhood.
肺功能（通常为 FEV1 <80%预计值）的测量用于成人和儿童的哮喘严重程度分类，尽管有证据表明，在儿科哮喘人群中，肺功能损害程度较轻。本研究评估了肺功能测量作为严重儿童哮喘鉴别诊断指标的相关性。
51 名有严重问题的学龄期儿童哮喘患者、37 名轻中度哮喘患者和 29 名健康对照者接受了全面的临床评估。严重问题性哮喘是指尽管接受高剂量吸入皮质激素治疗和至少一种其他哮喘控制药物治疗，但哮喘控制仍不佳的患者。轻中度哮喘儿童使用低剂量吸入类固醇，报告的哮喘症状极少。
有严重问题的哮喘儿童的基础 FEV1 值明显降低，但 FEV1 <80%预计值对区分严重与轻中度哮喘的敏感性较低（41%）。受试者工作特征分析估计，在该人群中，FEV1 的最佳截断值为 90%预计值（敏感性为 61%，特异性为 83%）。基础 FEV1/FVC 和 FEF（25-75）值在区分严重问题性哮喘方面并不优于 FEV1，呼气一氧化氮水平或支气管高反应性也不能区分这两种哮喘患者人群。
在儿童中，肺功能测量对严重问题性哮喘的鉴别诊断不敏感。
