Aqueous solute concentrations and evaluation of mass transport coefficients in peritoneal dialysis.
Aqueous solute concentrations and evaluation of mass transport coefficients in peritoneal dialysis.
复制标题
腹膜透析中的水溶质浓度和传质系数的评估。
DOI：
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发表时间：
1992
影响因子：
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通讯作者：
Bengt Lindholm
中科院分区：
文献类型：
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作者：
J. Waniewski;O. Heimbürger;A. Werynski;Bengt Lindholm
腹膜透析中小分子溶质的扩散和对流传质的定量描述取决于所研究物质浓度的准确测定和适当表达。对于易于在透析液和血浆之间平衡的小溶质，血浆中的溶质浓度应表示为每体积血浆水（水溶液浓度），而不是每体积全血浆。此外，如果用火焰光度法测量电解质，则应考虑唐南效应。表示每体积全血浆中溶质浓度（血浆浓度）的常见做法可能导致腹膜转运参数计算值出现实质性误差。为了量化这些误差，我们比较了使用3.86%葡萄糖透析液进行的28项6小时单次留置研究的血浆与水性透析液与血浆比（D/P）、扩散传质系数（KBD）和筛分系数（S）。对于除葡萄糖以外的所有物质，360 min时未校正血浆D/P高估校正水D/P 2%（钾和钠）至8%（肌酸酐），根据Pyle-Popovich模型评估，未校正大骨节病高估真实大骨节病12%（钾）至41%（尿素）。使用Garred模型和透析液等容期间估计的KBD也获得了类似的结果。使用水溶液而不是血浆浓度导致尿素的S发生实质性变化，但其他研究溶质的S未发生实质性变化。这些结果强调了在D/P比和传质系数的计算中，表达每体积血浆水而不是每体积整个血浆的小溶质浓度的重要性。
The quantitative description of diffusive and convective mass transport of small solutes in peritoneal dialysis is dependent on accurate determination and appropriate expression of the concentration of investigated substances. For small solutes which easily equilibrate between dialysate and plasma the solute concentration in plasma should be expressed per volume of plasma water (aqueous concentration) and not per volume of whole plasma. Furthermore, the Donnan effect should be taken into account for electrolytes if measured by flame photometry. The common practice of expressing solute concentration per volume of whole plasma (plasma concentration) may result in substantial errors in calculated values of peritoneal transport parameters. To quantify these errors we compared plasma versus aqueous dialysate to plasma ratios (D/P), diffusive mass transport coefficients (KBD), and sieving coefficients (S) for 28 6-h single-dwell studies using glucose 3.86% dialysis fluid. For all substances except glucose non-corrected plasma D/P overestimated corrected aqueous D/P at 360 min by 2% (potassium and sodium) to 8% (creatinine) and, as assessed by the Pyle-Popovich model, non-corrected KBD overestimated true KBD by 12% (potassium) to 41% (urea). Similar results were also obtained for KBD estimation using the Garred model and KBD estimated during dialysate isovolaemia. The use of aqueous instead of plasma concentrations resulted in a substantial change of S for urea but not for the other investigated solutes. These results emphasise the importance of expressing small solute concentrations per volume of plasma water and not per volume of whole plasma in calculations of D/P ratios and mass transport coefficients.