Department of Nutrition and Exercise Physiology, Washington State University-Health Sciences Spokane, Elson S. Floyd College of Medicine, Spokane, Washington.
Department of Medicine, University of Vermont, Vermont Lung Center, Burlington, Vermont.
Respir Care. 2021 Aug;66(8):1282-1290. doi: 10.4187/respcare.08421. Epub 2021 May 18.
The spirometric response to fast-acting bronchodilator is used clinically to diagnose asthma and in clinical research to verify its presence. However, bronchodilator responsiveness does not correlate with airway hyper-responsiveness measured with the direct-acting stimulus of methacholine, demonstrating that bronchodilator responsiveness is a problematic method for diagnosing asthma. The relationship between bronchodilator responsiveness and airway hyper-responsiveness assessed with indirect-acting stimuli is not known.
Retrospectively, the spirometric responses to inhaled bronchodilator and a eucapnic voluntary hyperpnea challenge (EVH) were compared in 39 non-smoking adult subjects with asthma (26 male, 13 female; mean ± SD age 26.9 ± 7.8 y; mean ± SD body mass index 26.3 ± 4.7 kg/m). All subjects met one or both of 2 criteria: ≥ 12% and 200 mL increase in FEV after inhaled bronchodilator, and ≥ 10% decrease in FEV after an EVH challenge.
Overall, FEV increased by 9.9 ± 7.9% after bronchodilator (3.93 ± 0.97 to 4.28 ± 0.91 L, < .001) and decreased by 23.9 ± 15.0% after the EVH challenge (3.89 ± 0.89 to 2.96 ± 0.88 L, < .001). However, the change in FEV after bronchodilator did not correlate with the change after EVH challenge (r = 0.062, = .71). Significant bronchodilator responsiveness predicted a positive response to EVH challenge in 9 of 33 subjects (sensitivity 27%). Following EVH, the change in FEV strongly correlated with the change in FVC (FEV percent change vs FVC percent change, r = 0.831, < .001; FEV ΔL vs FVC ΔL, r = 0.799, < .001).
These results extend previous findings that demonstrate a lack of association between bronchodilator responsiveness and methacholine responsiveness. Given the poor concordance between the spirometric response to fast-acting bronchodilator and the EVH challenge, these findings suggest that the airway response to inhaled β-agonist must be interpreted with caution and in the context of its determinants and limitations.
快速作用支气管扩张剂的肺量计反应临床上用于诊断哮喘，并在临床研究中验证其存在。然而，支气管扩张剂反应性与通过直接作用刺激物乙酰甲胆碱测量的气道高反应性不相关，表明支气管扩张剂反应性是诊断哮喘的有问题的方法。间接作用刺激物评估的支气管扩张剂反应性和气道高反应性之间的关系尚不清楚。
回顾性地，比较了 39 名非吸烟成年哮喘患者（26 名男性，13 名女性；平均年龄 26.9 ± 7.8 岁；平均体重指数 26.3 ± 4.7 kg/m）吸入支气管扩张剂和呼气末正压通气（EVH）挑战后的肺量计反应。所有患者均符合以下标准之一或两者：吸入支气管扩张剂后 FEV 增加≥12%和≥200 mL，或 EVH 挑战后 FEV 下降≥10%。
总体而言，支气管扩张剂后 FEV 增加 9.9 ± 7.9%（3.93 ± 0.97 至 4.28 ± 0.91 L， <.001），EVH 挑战后下降 23.9 ± 15.0%（3.89 ± 0.89 至 2.96 ± 0.88 L， <.001）。然而，支气管扩张剂后的 FEV 变化与 EVH 挑战后的 FEV 变化不相关（r = 0.062， =.71）。33 名患者中的 9 名（敏感性 27%）出现显著的支气管扩张剂反应性，预测对 EVH 挑战有阳性反应。EVH 后，FEV 的变化与 FVC 的变化密切相关（FEV 百分比变化与 FVC 百分比变化的关系，r = 0.831， <.001；FEV ΔL 与 FVC ΔL 的关系，r = 0.799， <.001）。
这些结果扩展了先前的研究结果，表明支气管扩张剂反应性与乙酰甲胆碱反应性之间缺乏关联。鉴于快速作用支气管扩张剂的肺量计反应与 EVH 挑战之间的一致性较差，这些发现表明必须谨慎解释吸入 β-激动剂后的气道反应，并考虑其决定因素和局限性。
