Agostoni E, Agostoni P G, Zocchi L
Istituto di Fisiologia Umana I, Università di Milano, Italy.
Respir Physiol. 1989 Mar;75(3):357-70. doi: 10.1016/0034-5687(89)90044-3.
Pleural liquid pressure in zone of apposition (Pliq,ap) and in lung zone (Pliq,L) was measured simultaneously through liquid filled cannulas in anesthetized dogs in lateral posture. At top Pliq,ap and Pliq,L at iso-height were -9.7 +/- 0.4 and -11.9 +/- 0.3 cm H2O, respectively, at end expiration (eE; P of delta less than 0.01; 11 dogs); -9.6 +/- 0.7 and -19.8 +/- 0.7 cm H2O at end inspiration (eI). At bottom they were -0.6 +/- 0.2 and -2.4 +/- 0.4 cm H2O, respectively, at eE (P of delta less than 0.05; 4 dogs); -1.5 +/- 0.3 and -8.5 +/- 1.0 cm H2O at eI. Vertical gradient of Pliq,ap was -0.97 +/- 0.02 cm H2O/cm. A 132% increase in ventilation (after 10 min dead space breathing) did not change eE and eI Pliq,ap, and eE Pliq,L, but decreased eI Pliq,L. These results imply: (1) no transmission to zone of apposition of tidal changes in Pliq,L; (2) a liquid flow from zone of apposition to lung zone; (3) a net filtration into zone of apposition. They suggest that absorption pressure of capillaries of visceral pleura is greater than that of lymphatics of zone of apposition. Lymphatic role in setting Pliq,L is discussed.
通过插入处于侧卧位的麻醉犬体内的充满液体的套管，同时测量贴附区（Pliq,ap）和肺区（Pliq,L）的胸液压。呼气末（eE）时，等高处的Pliq,ap和Pliq,L最高值分别为-9.7±0.4和-11.9±0.3 cmH₂O（δP＜0.01；11只犬）；吸气末（eI）时为-9.6±0.7和-19.8±0.7 cmH₂O。呼气末时，底部的Pliq,ap和Pliq,L分别为-0.6±0.2和-2.4±0.4 cmH₂O（δP＜0.05；4只犬）；吸气末时为-1.5±0.3和-8.5±1.0 cmH₂O。Pliq,ap的垂直梯度为-0.97±0.02 cmH₂O/cm。通气量增加132%（10分钟无效腔呼吸后）并未改变呼气末和吸气末的Pliq,ap以及呼气末的Pliq,L，但降低了吸气末的Pliq,L。这些结果表明：（1）Pliq,L的潮气量变化不会传导至贴附区；（2）液体从贴附区流向肺区；（3）有净滤过进入贴附区。提示脏胸膜毛细血管的吸收压力大于贴附区淋巴管的吸收压力。文中讨论了淋巴管在设定Pliq,L中的作用。
