Flessner M F
Laboratory of Kidney and Electrolyte Metabolism, National Institutes of Health, Bethesda, Md.
Blood Purif. 1992;10(3-4):136-47. doi: 10.1159/000170041.
'Net ultrafiltration' in peritoneal dialysis refers to the difference between the osmotically induced ultrafiltration into the peritoneal cavity and the fluid loss from the cavity during dialysis. Recent research has demonstrated that, during a 3- to 4-hour experimental dialysis, 5-25% of the total fluid loss is via lymphatics and the remaining fluid is absorbed directly into the tissue surrounding the peritoneal cavity. The driving force for this convection into tissue is the hydrostatic pressure gradient between the peritoneal cavity and the tissue, which ranges from 2 to 8 mm Hg during the typical 2-liter dialysis in humans. Because the convection from the cavity occurs during periods of a positive net ultrafiltration, the peritoneum and its underlying tissue cannot be represented as a single membrane but function as a composite of 'tight' and 'loose' membranes. More data on the mechanical properties of the peritoneal tissue space and its response to hydrostatic pressure in the cavity are required before we fully understand fluid transport at the tissue level.
腹膜透析中的“净超滤”是指渗透诱导的超滤进入腹膜腔与透析过程中腹腔内液体流失之间的差值。最近的研究表明，在3至4小时的实验性透析过程中，总液体流失的5%至25%是通过淋巴管排出的，其余液体则直接被吸收到腹膜腔周围的组织中。这种向组织内对流的驱动力是腹膜腔与组织之间的静水压梯度，在人体典型的2升透析过程中，该梯度范围为2至8毫米汞柱。由于腹腔内的对流发生在净超滤为正的时期，因此腹膜及其下方组织不能被视为单一膜，而是作为“紧密”和“疏松”膜的复合体发挥作用。在我们充分理解组织水平的液体运输之前，还需要更多关于腹膜组织间隙的力学特性及其对腹腔内静水压反应的数据。
