Albert R K, Lamm W J, Luchtel D L
Medical Service, Veterans Administration Medical Center, Seattle, Washington.
J Appl Physiol (1985). 1988 Jan;64(1):285-90. doi: 10.1152/jappl.1988.64.1.285.
Because of conflicting data in the literature, we studied the effect of positive-pressure inflation on transvascular fluid filtration in zone 1 lungs. Lungs from New Zealand White rabbits (n = 10) were excised, perfused with saline and autologous whole blood (1:1), ventilated, and continuously weighed. Pulmonary arterial and venous pressures (Pvas) were referenced to the most dependent part of the lung. A change in vascular volume (delta Vvas) and a fluid filtration rate (FFR) were calculated from the change in lung weight that occurred from 0 to 30 s and from 3 to 5 and 5 to 10 min, respectively, after changing alveolar pressure (PA). FFR's and delta Vvas's were measured with Pvas equal to 2 or 10 cmH2O and PA changing from 15 to 30 cmH2O when the lungs were normal and after they were made edematous. When Pvas = 2 cmH2O, increasing PA increased the Vvas and the FFR in both normal and edematous lungs. However, when Pvas = 10 cmH2O, increasing PA only slightly changed the Vvas and reduced the FFR in the normal lungs, and decreased Vvas and markedly decreased the FFR in the presence of edema. Inflating zone 1 lungs by positive pressure has an effect on transvascular fluid flux that depends on the Pvas. The results suggest that the sites of leakage in zone 1 also vary depending on Pvas and PA.
由于文献中的数据相互矛盾，我们研究了正压通气对1区肺组织跨血管液体滤过的影响。切除10只新西兰白兔的肺，用生理盐水和自体全血（1:1）进行灌注，进行通气，并持续称重。肺动脉压和静脉压（Pvas）以肺最下垂部位为参照。分别根据肺泡压（PA）改变后0至30秒、3至5分钟以及5至10分钟时肺重量的变化计算血管容量变化（delta Vvas）和液体滤过率（FFR）。在肺正常和水肿后，当Pvas等于2或10 cmH2O且PA从15 cmH2O变化至30 cmH2O时测量FFR和delta Vvas。当Pvas = 2 cmH2O时，在正常肺和水肿肺中，增加PA均会增加Vvas和FFR。然而，当Pvas = 10 cmH2O时，增加PA仅使正常肺中的Vvas略有变化并降低FFR，而在存在水肿时会使Vvas降低并显著降低FFR。对1区肺组织进行正压通气对跨血管液体通量有影响，这取决于Pvas。结果表明，1区的渗漏部位也因Pvas和PA而异。
