Effects of volume history during spontaneous and acutely induced air-flow obstruction in asthma.
Effects of volume history during spontaneous and acutely induced air-flow obstruction in asthma.
复制标题
哮喘自发性和急性气流阻塞期间容量历史的影响。
DOI：
10.1164/arrd.1987.135.3.591
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发表时间：
1987
期刊：
影响因子：
--
通讯作者：
IngramJr,RH
中科院分区：
文献类型：
--
作者：
Lim,TK;Pride,NB;IngramJr,RH
我们通过比较从FRC（部分，P）上方开始的强制呼气操作与从TLC（最大，M）开始的强制呼气操作在60% VC时对哮喘患者最大呼气流量（）的体积历史影响，并将结果表示为M-P比。在不同程度梗阻的临床人群中，我们发现M-P比率与梗阻过程的严重程度成反比，即梗阻越严重的患者在深吸入（DI）后跌倒。相比之下，轻度哮喘患者急性引起的同样严重的梗阻与DI后的增加相关。通过单次呼吸氮试验评估，自发组与诱导组在非均匀性程度上没有差异。自发性梗阻时灌注后气道比导度的变化方向与灌注后气道比导度的变化方向相同，且灌注后支气管收缩组气道通径恢复时间明显长于支气管扩张组。我们的结论是，在自发性梗阻的严重支气管哮喘中，与急性梗阻相反，DI会导致严重程度的增加，并且重建基线气道口径的时间更长。我们认为两组之间梗阻的机制和部位不同。
We examined the volume history effect on maximal expiratory flow () in patients with asthma by comparing at 60% of VC from forced exhalation maneuvers begun just above FRC (partial, P) with those begun from TLC (maximal, M) and expressed the results as M-P ratios. In a clinic population with varying degrees of obstruction, we found that M-P ratios varied inversely with the severity of the obstructive process, i.e., the more severely obstructed patients had a fall in after a deep inhalation (DI). By contrast, equally severe obstruction acutely induced in subjects with mild asthma was associated with an increase in after a DI. There was no difference between the spontaneous versus the induced groups in degree of nonhomogeneity as assessed by single-breath nitrogen tests. Changes in specific airway conductance after a DI during spontaneous obstruction were in the same direction as the changes in , and the time course for restitution of airway caliber in subjects who showed bronchoconstriction after a DI was significantly longer than for those subjects who showed bronchodilatation. We conclude that in severe bronchial asthma with spontaneous obstruction, a DI produces an increase in severity that is opposite to the results found in acutely induced obstruction, and the time course for reestablishing baseline airway caliber is more prolonged. We suggest that mechanisms for and sites of obstruction vary between the 2 groups.