Bates J H, Sly P D, Kochi T, Martin J G
Meakins-Christie Laboratories, McGill University, Montreal, Quebec, Canada.
Respir Physiol. 1987 Dec;70(3):301-12. doi: 10.1016/0034-5687(87)90012-0.
The interrupter method for measuring respiratory system resistance involves rapidly interrupting flow at the airway opening while measuring the pressure just distal to the site of interruption. In general, the pressure signal obtained exhibits an initial rapid change (delta Pinit) accompanied by rapid damped oscillations, followed by a further slow change to a steady-state plateau level. Delta Pinit is thought to principally reflect the resistance of the pulmonary airways Raw. We have developed a computer model capable of simulating the main features observed in an interrupter pressure signal. We show that the distinct phases in the pressure signal can be obscured by the existence of a compliant compartment between the airways and the occluding valve (e.g. the cheeks and pharynx) when Raw is increased. Our results suggest that supporting the cheeks may enable one to estimate Raw with the interrupter technique in the presence of mild to moderate bronchoconstriction, but that with severe bronchoconstriction (Raw increased 10-fold above normal) it may not be possible.
测量呼吸系统阻力的阻断法是在气道开口处快速阻断气流的同时，测量阻断部位远端的压力。一般来说，所获得的压力信号呈现出一个初始的快速变化（δPinit），伴有快速衰减的振荡，随后进一步缓慢变化至稳态平台水平。δPinit被认为主要反映肺气道阻力Raw。我们开发了一个计算机模型，能够模拟在阻断压力信号中观察到的主要特征。我们发现，当Raw增加时，气道与阻断阀之间存在顺应性腔室（如脸颊和咽部）会使压力信号中的不同阶段变得模糊。我们的结果表明，在存在轻度至中度支气管收缩的情况下，托住脸颊可能使人们能够用阻断技术估计Raw，但在严重支气管收缩（Raw比正常增加10倍）时可能无法做到。
