Funck-Brentano J L
Artif Organs. 1981 Feb;5(1):51-3.
Water shift between intra- and extracellular body compartments is under osmotic pressure driving forces. Assuming that the cellular membrane is impermeable to Na, any change in extracellular Na concentration induces an osmotic pressure difference between the two compartments and results in water transfer in order to equilibrate osmotic pressures between body compartments. Ultrafiltration per se2-4 does not induce any change in plasma Na concentration. Thus, no water transfer occurs between the body compartments. Hemodialysis performed with a Na concentration in the dialysate different from that of the plasma induces a water flux between intra- and extracellular spaces. When using a closed batch dialysate delivery system, it becomes possible to measure the Na mass balance and then to get an accurate pattern of Na and water transfer between the body and the batch. First I would like to describe the Na-free water clearance concept. Then I will show how the increase of Na-free water clearance explains the tolerance of BW and blood pressure to high Na concentration in the dialysate.
体内细胞内液和细胞外液之间的水转移受渗透压驱动力的影响。假设细胞膜对钠离子不通透，细胞外钠离子浓度的任何变化都会在两个腔室之间产生渗透压差异，并导致水的转移，以平衡体内各腔室之间的渗透压。超滤本身2-4不会引起血浆钠浓度的任何变化。因此，体内各腔室之间不会发生水的转移。使用与血浆钠浓度不同的透析液进行血液透析会在细胞内和细胞外空间之间诱导水通量。当使用封闭式批量透析液输送系统时，就可以测量钠质量平衡，进而获得体内与批量之间钠和水转移的准确模式。首先，我想描述无钠水清除率的概念。然后我将展示无钠水清除率的增加如何解释体重和血压对透析液中高钠浓度的耐受性。
