Giannini D, Paggiaro P L, Moscato G, Gherson G, Bacci E, Bancalari L, Dente F L, Di Franco A, Vagaggini B, Giuntini C
2nd Institute of Internal Medicine, Respiratory Pathophysiology, Pisa, Italy.
J Asthma. 1997;34(2):105-11. doi: 10.3109/02770909709075654.
To evaluate the sensitivity of peak expiratory flow (PEF), obtained by portable peak flow meter, in detecting mild changes in airway caliber as assessed by forced expiratory volume in 1 sec (FEV1), we studied 184 subjects who underwent different bronchial challenge tests for suspected bronchial asthma. We measured FEV1 and PEF during bronchoconstriction induced by different stimuli: allergen, methacholine, toluene diisocyanate vapors, exercise, or distilled water inhalation; a total of 186 tests were examined. Before and at different times after challenge, FEV1 was measured, and immediately after, PEF was obtained by Mini-Wright or Assess Peak Flow Meter; each time FEV1 and PEF were taken as the best of three satisfactory tracings. The median FEV1 change from baseline value of all steps in the different challenge tests was 7.5% (range: 0-66%). The correlation coefficients between FEV1 and PEF percent changes in different challenge tests were low (Spearman's p: 0.27-0.69), with high scattering of the data. The concordance between classes of percent changes in FEV1 and PEF was also low (Cohen's weighted kappa: 0.28-0.42). In subjects with a FEV1 fall > 15% after challenge, the median PEF change after bronchoconstriction was lower than the corresponding FEV1 change [17% (0-52) vs. 27% (17-66)]. When different cutoff limits of PEF percent change were considered, the sensitivity of PEF to detect a significant change in FEV1 (15 or 20% change) during bronchoconstriction was low; specificity was in general higher than sensitivity. We conclude that PEF and FEV1 changes are poorly related during mild bronchoconstriction induced by different stimuli. The low sensitivity of PEF to detect mild changes in airway caliber may represent a limit in the use of PEF in the day-to-day monitoring of asthma.
为了评估便携式峰值流量计测得的呼气峰值流速（PEF）在检测气道管径轻微变化方面的敏感性，这种变化通过第1秒用力呼气量（FEV1）来评估，我们研究了184名因疑似支气管哮喘而接受不同支气管激发试验的受试者。我们在由不同刺激物诱发的支气管收缩过程中测量了FEV1和PEF，这些刺激物包括变应原、乙酰甲胆碱、甲苯二异氰酸酯蒸气、运动或吸入蒸馏水；总共检查了186次试验。在激发前和激发后的不同时间测量FEV1，并在激发后立即用Mini-Wright或评估峰值流量计获得PEF；每次FEV1和PEF均取三次满意描记中的最佳值。在不同激发试验的所有步骤中，FEV1相对于基线值的变化中位数为7.5%（范围：0 - 66%）。不同激发试验中FEV1和PEF百分比变化之间的相关系数较低（Spearman氏p值：0.27 - 0.69），数据离散度较高。FEV1和PEF百分比变化类别之间的一致性也较低（Cohen加权kappa值：0.28 - 0.42）。在激发后FEV1下降>15%的受试者中，支气管收缩后PEF变化的中位数低于相应的FEV1变化[17%（0 - 52）对27%（17 - 66）]。当考虑PEF百分比变化的不同截断值时，PEF在支气管收缩期间检测FEV1显著变化（15%或20%变化）的敏感性较低；特异性总体上高于敏感性。我们得出结论，在由不同刺激物诱发的轻度支气管收缩过程中，PEF和FEV1的变化相关性较差。PEF检测气道管径轻微变化的低敏感性可能代表了其在哮喘日常监测中应用的一个局限。
