肺水肿是肺功能不全的一个重要组成部份。解剖上,肺不同于其它器官,除间质外尚有一个巨大的潜在水间隙即肺泡间隙。正常情况下,高分子物质几乎不能通透肺泡内皮屏障。液体从肺泡间隔移出的原因是间质压力梯度集结的结果,其压力梯度越近肺门越趋于负压,所以即使中等度水肿,肺泡壁的水含量亦 Pulmonary edema is an important component of pulmonary insufficiency. Anatomically, unlike other organs, the lung has a huge potential water gap, alveolar space, in addition to the stroma. Under normal circumstances, the polymer material barely permeable alveolar endothelial barrier. The reason for the fluid to move out of the alveolar space is the result of an interstitial pressure gradient build-up. The closer the pressure gradient to the hilar, the more negative the pressure, so even with moderate edema, the water content of the alveolar walls