Oscillation mechanics of the human lung periphery in asthma.
Oscillation mechanics of the human lung periphery in asthma.
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哮喘中人肺周围的振荡机制。
DOI：
10.1152/japplphysiol.00300.2004
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
Bates,JasonHT
中科院分区：
文献类型：
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作者：
Kaminsky,DavidA;Irvin,CharlesG;Lundblad,Lennart;Moriya,HenriqueT;Lang,Sherburn;Allen,Jennifer;Viola,Tracey;Lynn,Mary;Bates,JasonHT
为了更精确地测量哮喘患者肺外周的机械特性，我们开发了一种通过楔形支气管镜施加宽带流量信号的强迫振荡技术。我们解释的数据，从四个健康和八个轻度哮喘受试者在解剖学上准确的计算机模型的楔形段。两组之间的阻抗存在大量重叠，电阻（R）显示出最小的频率依赖性，弹性（E）显示出受试者之间的正和负频率依赖性。在直接滴入乙酰甲胆碱后，两组的R均上升，但与健康受试者相比，哮喘受试者的剂量-反应曲线显示出向上的平行移动。乙酰甲胆碱后E的基线频率反应模式增强。频率依赖性的R和E在两个正常人的计算模型，采用刚性气道连接到恒定相位的组织单位，但更好地再现在其他两个正常和三个哮喘受试者时，该模型采用异质性，外周气道狭窄和顺应性气道。为了捕获其余5名哮喘受试者中R和E的频率依赖性，通过增加气道壁刚度来修改模型。这些结果表明，轻度哮喘受试者的肺外周在基线时通过测量机械阻抗不能很好地与健康受试者区分开，但在乙酰甲胆碱激发后观察到组间差异。响应的建模表明，气道狭窄和壁顺应性的可变贡献在确定患有哮喘的人的肺外周的总体机械阻抗中是有效的，这可能反映了气道炎症和重塑的功能后果。
To more precisely measure the mechanical properties of the lung periphery in asthma, we have developed a forced oscillation technique that applies a broad-band flow signal through a wedged bronchoscope. We interpreted the data from four healthy and eight mildly asthmatic subjects in terms of an anatomically accurate computer model of the wedged segment. There was substantial overlap in impedance between the two groups, with resistance (R) showing minimal frequency dependence and elastance (E) showing positive and negative frequency dependence across subjects. After direct instillation of methacholine, R rose in both groups, but compared with healthy subjects, the asthmatic subjects displayed upward, parallel shifts in their dose-response curves. The baseline frequency-response patterns of E were enhanced after methacholine. Frequency dependencies of R and E were well reproduced in two normal subjects by a computational model that employed rigid airways connected to constant-phase tissue units but were better reproduced in the other two normal and three asthmatic subjects when the model employed heterogeneous, peripheral airway narrowing and compliant airways. To capture the frequency dependencies of R and E in the remaining five asthmatic subjects, the model was modified by increasing airway wall stiffness. These results indicate that the lung periphery of mildly asthmatic subjects is not well distinguished from that of healthy subjects by measurement of mechanical impedance at baseline, but group differences are seen after challenge with methacholine. Modeling of the response suggests that variable contributions of airway narrowing and wall compliance are operative in determining overall mechanical impedance of the lung periphery in humans with asthma, likely reflecting the functional consequences of airway inflammation and remodeling.