Staub N C, Gee M, Vreim C
Ciba Found Symp. 1976(38):255-72. doi: 10.1002/9780470720202.ch15.
In severe pulmonary oedema, the alveoli fill rapidly with fluid of essentially the same protein composition as free interstitial fluid. The usual explanation is that the normally 'tight' alveolar epithelial intercellular junctions suddenly become freely permeable to proteins. But the pathophysiological basis for such a change is unknown. In seven anaesthetized dogs one lower lobe was filled with iso-osmotic fluid containing 125I-labelled albumin. The calculated alveolus-blood albumin permeability over three hours averaged 0.06 X 10(-7) cm/s. It decreased nearly 50% when the alveolar tracer concentration was tripled for three more hours. At autopsy, large interstitial free fluid cuffs around blood vessels and airways were found. Isolated lung lobes were filled with isosmotic fluid containing tracer albumin at 10 and 20 cmH2O (0.98-1.96 kPa) airway pressure. Free interstitial fluid cuffs developed within 30 and 10 minutes, respectively. The tracer protein concentration in the cuff fluid averaged 0.9 that of the alveolar fluid. It is postulated that the terminal airway epithelium is normally permeable to protein and water. In acute pulmonary oedema alveolar flooding may occur along the same pathway after the loose interstitial tissue space is fluid-filled and its pressure exceeds that in the airway. The anatomical site of the bulk fluid and protein leak has not been identified.
在严重肺水肿时，肺泡迅速被蛋白质成分与游离间质液基本相同的液体充满。通常的解释是，正常情况下“紧密”的肺泡上皮细胞间连接突然对蛋白质变得自由通透。但这种变化的病理生理基础尚不清楚。在7只麻醉犬中，一个下叶被充满含125I标记白蛋白的等渗液。计算得出的三小时内肺泡-血液白蛋白通透性平均为0.06×10(-7)厘米/秒。当肺泡示踪剂浓度在接下来的三小时内增加两倍时，它下降了近50%。尸检时，发现血管和气道周围有大量间质游离液袖套。在气道压力为10和20厘米水柱（0.98 - 1.96千帕）时，将离体肺叶充满含示踪白蛋白的等渗液。分别在30分钟和10分钟内出现了游离间质液袖套。袖套液中的示踪蛋白浓度平均为肺泡液的0.9倍。据推测，终末气道上皮通常对蛋白质和水是通透的。在急性肺水肿时，当疏松的间质组织间隙充满液体且其压力超过气道压力后，肺泡灌流可能沿相同途径发生。大量液体和蛋白质渗漏的解剖部位尚未确定。
