den Otter J J, Reijnen G M, van den Bosch W J, van Schayck C P, Molema J, van Weel C
Department of General Practice and Social Medicine, Nijmegen University, The Netherlands.
Br J Gen Pract. 1997 Aug;47(421):487-92.
Assessing bronchial hyper-responsiveness (BHR) is a main diagnostic criterion of asthma. Provocation testing is not readily available in general practice, but peak expiratory flow (PEF) is. Several guidelines promote the use of PEF variability as a diagnostic tool for BHR. This study tested the agreement between histamine challenge testing and PEF variability, and the consequences for diagnosing asthma.
To investigate the possibility of assessing BHR by PEF variability, using a histamine provocation test as a reference.
Subjects with signs of symptoms indicating asthma (persistent or recurrent respiratory symptoms or signs of reversible bronchial obstruction) (n = 323) were studied. They had been identified in a population screening for asthma. A histamine provocation test and PEF variability were assessed over a three-week period. Asthma was defined as signs or symptoms together with a reversible airflow obstruction or BHR to the histamine challenge test. BHR was defined as a PC20 histamine of < or = 8 mg/ml or a PEF variability of > or = 15%. Overall correlation between PC20 and PEF variability was calculated using Spearman's rho. Furthermore, a decision tree was constructed to clarify the role of BHR in diagnosing asthma.
Thirty-two patients had a reversibility in forced expiratory volume in 1 second (FEV1) of > or = 9% predicted, 131 patients showed a PC20 of < or = 8 and 11 patients had a PEF variability of > or = 15%. Overall correlation was poor at only -0.27 (P < 0.0001). One hundred and fourteen of the 131 patients diagnosed as having asthma when the histamine challenge test was used were not diagnosed by PEF variability.
PEF variability cannot replace bronchial provocation testing in assessing BHR. This indicates that PEF variability and bronchial provocation do not measure the same aspects of BHR. If BHR testing is required in diagnosing asthma, a bronchial provocation test has to be used in general practice as well.
评估支气管高反应性（BHR）是哮喘的主要诊断标准。激发试验在普通医疗实践中不易获得，但呼气峰值流速（PEF）则不然。多项指南提倡将PEF变异性用作BHR的诊断工具。本研究检验了组胺激发试验与PEF变异性之间的一致性，以及对哮喘诊断的影响。
以组胺激发试验为参考，研究通过PEF变异性评估BHR的可能性。
对有哮喘症状体征（持续性或复发性呼吸道症状或可逆性支气管阻塞体征）的受试者（n = 323）进行研究。这些受试者是在哮喘人群筛查中被识别出来的。在三周时间内评估组胺激发试验和PEF变异性。哮喘定义为伴有可逆性气流受限或对组胺激发试验的BHR的症状体征。BHR定义为组胺激发浓度20（PC20）≤8mg/ml或PEF变异性≥15%。使用Spearman等级相关系数计算PC20与PEF变异性之间的总体相关性。此外，构建决策树以阐明BHR在哮喘诊断中的作用。
32例患者1秒用力呼气容积（FEV1）的可逆性≥预测值的9%，131例患者的PC20≤8，11例患者的PEF变异性≥15%。总体相关性较差，仅为-0.27（P < 0.0001）。在使用组胺激发试验诊断为哮喘的131例患者中，有114例未被PEF变异性诊断出来。
在评估BHR时，PEF变异性不能替代支气管激发试验。这表明PEF变异性和支气管激发试验测量的不是BHR的同一方面。如果在哮喘诊断中需要进行BHR检测，在普通医疗实践中也必须使用支气管激发试验。
