Jones J G, Graf P D, Lemen R
Br J Anaesth. 1978 Aug;50(8):735-42. doi: 10.1093/bja/50.8.735.
Critical narrowing of the dependent airways was examined in anaesthetized dogs with closed chests. Two techniques were used, (a) "closing" volume (CV), measured from the expired nitrogen plateau and (b) tantalum bronchography, to measure the calibre of airways of 3-8 mm diameter in the upper (UZ), middle (MZ) and lower (LZ) zones. The point of airway "closure" at the junction of phases III and IV of the alveolar plateau coincided with an inflection in the diameter-lung volume curve of the airways in the most basal zone of the lung. This was accompanied by a sudden large increase in the calculated resistance of the airways in LZ compared with UZ. Following stimulation of the vagi CV increased and there was increased narrowing of airways, particularly in LZ. The addition of 0.5% halothane to the anaesthetic abolished the effect of vagal stimulation on CV and on airway resistance.
在麻醉的开胸犬中检查了依赖气道的临界狭窄情况。采用了两种技术，(a) 从呼出氮气平台测量的“闭合”容积（CV），以及 (b) 钽支气管造影术，以测量上（UZ）、中（MZ）和下（LZ）区直径为 3 - 8 毫米气道的管径。肺泡平台 III 期和 IV 期交界处气道“闭合”点与肺最基底部区域气道直径 - 肺容积曲线的拐点一致。这伴随着 LZ 气道计算阻力相较于 UZ 突然大幅增加。刺激迷走神经后，CV 增加，气道狭窄加剧，尤其是在 LZ。在麻醉剂中添加 0.5% 氟烷消除了迷走神经刺激对 CV 和气道阻力的影响。
