Hanson W L, Emhardt J D, Bartek J P, Latham L P, Checkley L L, Capen R L, Wagner W W
Department of Anesthesiology, Indiana University School of Medicine, Indianapolis 46223.
J Appl Physiol (1985). 1989 May;66(5):2079-83. doi: 10.1152/jappl.1989.66.5.2079.
Increasing the total surface area of the pulmonary blood-gas interface by capillary recruitment is an important factor in maintaining adequate oxygenation when metabolic demands increase. Capillaries are known to be recruited during conditions that raise pulmonary blood flow and pressure. To determine whether pulmonary arterioles and venules are part of the recruitment process, we made in vivo microscopic observations of the subpleural microcirculation (all vessels less than 100 microns) in the upper lung where blood flow is low (zone 2). To evoke recruitment, pulmonary arterial pressure was elevated either by an intravascular fluid load or by airway hypoxia. Of 209 arteriolar segments compared during low and high pulmonary arterial pressures, none recruited or derecruited. Elevated arterial pressure, however, did increase the number of perfused capillary segments by 96% with hypoxia and 165% with fluid load. Recruitment was essentially absent in venules (4 cases of recruitment in 289 segments as pressure was raised). These data support the concept that recruitment in the pulmonary circulation is exclusively a capillary event.
通过毛细血管募集增加肺气血界面的总表面积是在代谢需求增加时维持充分氧合的一个重要因素。已知在肺血流量和压力升高的情况下会发生毛细血管募集。为了确定肺小动脉和小静脉是否参与募集过程，我们对肺上部血流较低（2区）的胸膜下微循环（所有直径小于100微米的血管）进行了体内显微镜观察。为了诱发募集，通过血管内液体负荷或气道缺氧升高肺动脉压。在低肺动脉压和高肺动脉压期间比较的209个小动脉节段中，没有一个出现募集或解募集。然而，升高的动脉压在缺氧时使灌注的毛细血管节段数量增加了96%，在液体负荷时增加了165%。小静脉基本不存在募集现象（压力升高时，289个节段中有4个出现募集）。这些数据支持了肺循环中的募集完全是毛细血管事件的概念。
