The bronchoprotective effect of deep inspiration is flow rate dependent.
The bronchoprotective effect of deep inspiration is flow rate dependent.
复制标题
深吸气的支气管保护作用取决于流速。
DOI：
10.1016/j.rmed.2007.02.001
复制
发表时间：
2007
影响因子：
4.3
通讯作者：
Togias,Alkis
中科院分区：
文献类型：
--
作者：
Skloot,GwenS;Chandy,Dipak;Schachter,Neil;Togias,Alkis
背景和研究目的：在健康受试者中，深吸气（DI）可预防乙酰甲胆碱诱导的支气管收缩。我们假设DI的支气管保护作用取决于吸气流速。设计：前瞻性对照研究。单位：一家大型三级医疗中心内的肺功能实验室。参与者：10名健康非吸烟者，无哮喘或鼻炎。测量：首先，我们在没有DI的情况下进行乙酰甲胆碱激发，以确定足以使FEV 1降低20%的浓度。在随后的两天，在乙酰甲胆碱阈值浓度之前立即加入快速或慢速DI重复攻击。我们计算了FEV 1和FVC相对于基线的降低百分比。研究结果：快速DI组FEV 1和FVC的平均下降百分比显著低于无DI组（FEV 1为20±3% vs. 34±4%，p=0.02; FVC为12±3% vs. 23±3%，p=0.03）;缓慢DI对乙酰甲胆碱诱导的肺功能下降无显著影响。结论：快速DI具有支气管保护作用，而慢速DI则无此作用。阐明健康受试者中最大化或消除支气管保护作用的条件可能最终提供对哮喘病理生理学的深入了解。
BACKGROUND AND STUDY OBJECTIVE: Deep inspiration (DI) protects against methacholine-induced bronchoconstriction in healthy subjects. We hypothesized that this bronchoprotective effect of DI depends upon the inspiratory flow rate. DESIGN: Prospective, controlled study. SETTING: Pulmonary function laboratory within a large tertiary medical center. PARTICIPANTS: Ten healthy nonsmokers without asthma or rhinitis. MEASUREMENTS: First, we performed a methacholine challenge in the absence of DI to determine the concentration sufficient to reduce FEV1by 20%. On two subsequent days, the challenge was repeated with the addition of either a fast or slow DI immediately before the threshold concentration of methacholine. We calculated the % reduction in FEV1and FVC from baseline. RESULTS: Mean % reduction in FEV1and FVC was significantly less with a fast DI than with no DI (20±3% vs. 34±4% for FEV1, p=0.02; 12±3% vs. 23±3% for FVC, p=0.03); slow DIs did not significantly affect the methacholine-induced reduction in lung function. CONCLUSION: A fast DI is bronchoprotective while a slow DI is not. Elucidating the conditions that maximize or alternatively, eliminate bronchoprotection in healthy subjects may ultimately provide insight into the pathophysiology of asthma.