Demedts M, de Roo M, Cosemans J, Billiet L, van de Woestijne K P
J Appl Physiol. 1976 Aug;41(2):185-90. doi: 10.1152/jappl.1976.41.2.185.
In patients with chronic obstructive lung disease, we determined single-breath N2 and 133 Xe washout curves, and regional distributions of volumes (Vr) and of 133Xe boluses inhaled at residual volume (VIRV). Patients suffering from emphysema with minimal airway obstruction demonstrated large closing volumes and apicobasal distribution gradients, apparently because of a steep pulmonary recoil pressure-volume curve. In one subject with basal small airway disease there was no vertical gradient in regional residual volume; closing volume was increased with the 133Xe technique but almost absent with the N2 technique. Patients with moderate-to-severe airway obstruction had upward-sloping alveolar plateaus without distinct phase IV, and small apicobasal differences in Vr and VIRV. The latter resulted probably from increased regional differences in time constants counteracting the influence of gravity. Finally, patients with severe airway obstruction and basal emphysema demonstrated a rising N2 but a descending 133Xe plateau; the gradient for VIRV was normal, and reversed for Vr. This pattern was attributed to nongravitational differences in time constants causing a first in-first out distribution.
在慢性阻塞性肺疾病患者中，我们测定了单次呼吸氮气和133氙洗脱曲线，以及残气量时吸入的133氙团注的容积（Vr）和区域分布（VIRV）。患有轻度气道阻塞的肺气肿患者表现出较大的闭合气量和尖基底分布梯度，这显然是由于陡峭的肺弹性回缩压力-容积曲线所致。在一名患有基底小气道疾病的受试者中，区域残气量没有垂直梯度；用133氙技术测定的闭合气量增加，但用氮气技术测定时几乎不存在。中重度气道阻塞患者的肺泡平台呈上升趋势，无明显的IV期，Vr和VIRV的尖基底差异较小。后者可能是由于时间常数的区域差异增加，抵消了重力的影响。最后，患有严重气道阻塞和基底肺气肿的患者表现出氮气上升但133氙平台下降；VIRV的梯度正常，而Vr的梯度相反。这种模式归因于时间常数的非重力差异导致的先入先出分布。
