Department of Medicine, VA Palo Alto HCS and Stanford University, 3801 Miranda Avenue, Palo Alto, CA 94303, USA.
Clin J Am Soc Nephrol. 2011 Feb;6(2):290-6. doi: 10.2215/CJN.06100710. Epub 2010 Oct 28.
This study evaluated the contribution of residual function to the removal of solutes for which protein binding limits clearance by hemdialysis.
DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Solute concentrations were measured in 25 hemodialysis patients with residual urea clearances ranging from 0.1 to 6.2 ml/min per 1.73 m2. Mathematical modeling assessed the effect of residual function on time-averaged solute concentrations.
Dialytic clearances of the protein-bound solutes p-cresol sulfate, indoxyl sulfate, and hippurate were reduced in proportion to the avidity of binding and averaged 8±2, 10±3, and 44±13% of the dialytic urea clearance. For each bound solute, the residual clearance was larger in relation to the residual urea clearance. Residual kidney function therefore removed a larger portion of each of the bound solutes than of urea. Increasing residual function was associated with lower plasma levels of p-cresol sulfate and hippurate but not indoxyl sulfate. Wide variation in solute generation tended to obscure the dependence of plasma solute levels on residual function. Mathematical modeling that corrected for this variation indicated that increasing residual function will reduce the plasma level of each of the bound solutes more than the plasma level of urea.
In comparison to urea, solutes than bind to plasma proteins can be more effectively cleared by residual function than by hemodialysis. Levels of such solutes will be lower in patients with residual function than in patients without residual function even if the dialysis dose is reduced based on measurement of residual urea clearance in accord with current guidelines.
本研究评估了残余肾功能对蛋白质结合限制血液透析清除率的溶质的清除作用。
设计、设置、参与者和测量：在 25 名残余尿素清除率范围为 0.1 至 6.2ml/min/1.73m2 的血液透析患者中测量了溶质浓度。数学模型评估了残余功能对溶质平均浓度的影响。
与结合亲和力成比例，蛋白结合溶质对甲酚硫酸酯、吲哚硫酸酯和马尿酸的透析清除率降低，平均为透析尿素清除率的 8±2%、10±3%和 44±13%。对于每种结合的溶质，残余清除率与残余尿素清除率的关系更大。因此，残余肾功能对每种结合溶质的清除率都大于对尿素的清除率。残余肾功能的增加与血浆中甲酚硫酸酯和马尿酸水平降低相关，但与吲哚硫酸酯无关。溶质生成的广泛变异性往往掩盖了血浆溶质水平对残余功能的依赖关系。对这种变异性进行校正的数学模型表明，随着残余功能的增加，与血浆中尿素水平相比，每种结合溶质的血浆水平将降低更多。
与尿素相比，与血浆蛋白结合的溶质可以通过残余肾功能更有效地清除。即使根据当前指南基于残余尿素清除率的测量来减少透析剂量，残余功能的患者的这些溶质的水平将低于无残余功能的患者。
