Salmon R B, Primiano F P, Saidel G M, Niewoehner D E
J Appl Physiol Respir Environ Exerc Physiol. 1981 Aug;51(2):353-62. doi: 10.1152/jappl.1981.51.2.353.
We investigated the effect of airway closure and alveolar collapse on the large-volume deflation and inflation transpulmonary pressure-volume (Ptp-V) curves of five postmortem excised human lungs. For stepwise static cycles, no inflection occurred on the deflation curve, while either one or two inflections occurred on the inflation curve. These relations were stimulated by a multicompartment model, which assumed a bimodal distribution of compartmental collapse-pressure differences. The simulations indicate that alveolar collapse can occur without causing an inflection on the deflation curve and that hysteresis in reopening of collapsed alveoli on inflation can account for a major portion of Ptp-V hysteresis. In contrast, for slow dynamic cycles, an inflection occurred on the experimental deflation Ptp-V curve, and when inflations were begun at sufficiently low volumes, volume did not change until a threshold pressure difference was reached about which PtP began to oscillate as lung volume increased. These differences in the stepwise static and dynamic Ptp-V curves can result from sustained airway closure on deflation and popping-opening on inflation.
我们研究了气道关闭和肺泡萎陷对五例死后切除的人肺大容量放气和充气时跨肺压力-容积（Ptp-V）曲线的影响。对于逐步静态循环，放气曲线上未出现拐点，而充气曲线上出现了一个或两个拐点。这些关系由一个多室模型模拟得出，该模型假设室萎陷压力差呈双峰分布。模拟结果表明，肺泡萎陷可在不引起放气曲线出现拐点的情况下发生，并且充气时萎陷肺泡重新开放的滞后现象可解释Ptp-V滞后现象的主要部分。相比之下，对于缓慢动态循环，实验性放气Ptp-V曲线上出现了一个拐点，并且当在足够低的容积下开始充气时，在达到阈值压力差之前容积不变，在该阈值压力差附近，随着肺容积增加Ptp开始振荡。逐步静态和动态Ptp-V曲线的这些差异可能源于放气时气道持续关闭和充气时突然开放。
