Polosa R, Prosperini G, Magrì S, Ciamarra I, Pagano C, Paolino G, Santonocito G, Crimi N
Istituto Malattie Apparato Respiratorio, Universita' di Catania, Italy.
Eur Respir J. 1998 May;11(5):1086-90. doi: 10.1183/09031936.98.11051086.
Assessment of airway responsiveness by bronchoprovocation and bronchodilatation tests is important in the diagnostic work-up protocol of bronchial asthma and it would be convenient to undertake both tests on the same occasion. However, it is not known whether this can be done accurately. Therefore, this study evaluated the effect of a prior bronchial provocation test on the bronchodilator response to salbutamol after spontaneous recovery of the forced expiratory volume in one second (FEV1) in a group of asthmatic subjects. On two separate occasions at the same time of day, concentration-response studies with inhaled histamine or methacholine, or a sham challenge with normal saline were carried out in a blinded, randomized manner. Changes in airway calibre were followed as FEV1 and agonist responsiveness expressed as the provocative concentration causing a 20% fall in FEV1 (PC20). After either spontaneous recovery or a fixed-duration wait of 45 min (when appropriate), the subjects received 2x100 microg of salbutamol from a metered dose inhaler with a spacer. The bronchodilator response to salbutamol was expressed as a percentage of initial FEV1 (deltaFEV1% init). Bronchial challenge with both agonists failed to alter significantly the airway response to salbutamol, with the deltaFEV1% init mean value (range) being 16.9% (9.0-31.9) and 17.5% (11.6-31.2) on the sham and histamine/methacholine challenge day respectively. It was shown that the degree of bronchodilatation achieved after salbutamol 200 microg is not affected by prior bronchoprovocation testing when enough time is allowed for the airways to recover spontaneously to baseline forced expiratory volume in one second. Thus evaluation of airway responsiveness by both bronchial provocation tests and bronchodilator testing can be assessed reliably within a few hours in asthmatic patients.
通过支气管激发试验和支气管舒张试验评估气道反应性在支气管哮喘的诊断检查方案中很重要，并且在同一场合进行这两种试验会很方便。然而，尚不清楚这样做是否能准确进行。因此，本研究评估了在一组哮喘患者中，在一秒用力呼气容积（FEV1）自发恢复后，先前的支气管激发试验对沙丁胺醇支气管舒张反应的影响。在一天中的同一时间的两个不同场合，以盲法、随机方式进行吸入组胺或乙酰甲胆碱的浓度-反应研究，或用生理盐水进行假激发试验。跟踪气道口径的变化，以FEV1和激动剂反应性表示，激动剂反应性以导致FEV1下降20%的激发浓度（PC20）表示。在自发恢复或适当情况下固定等待45分钟后，受试者从带有储雾罐的定量吸入器中吸入2×100微克沙丁胺醇。对沙丁胺醇的支气管舒张反应以初始FEV1的百分比表示（δFEV1%初始）。两种激动剂的支气管激发均未显著改变对沙丁胺醇的气道反应，在假激发日和组胺/乙酰甲胆碱激发日，δFEV1%初始平均值（范围）分别为16.9%（9.0 - 31.9）和17.5%（11.6 - 31.2）。结果表明，当有足够时间让气道自发恢复到基线一秒用力呼气容积时，200微克沙丁胺醇后的支气管舒张程度不受先前支气管激发试验的影响。因此，在哮喘患者中，支气管激发试验和支气管舒张试验评估气道反应性可在数小时内可靠地进行。
