La Milia V, Di Filippo S, Crepaldi M, Andrulli S, Marai P, Bacchini G, Del Vecchio L, Locatelli F
Department of Nephrology and Dialysis, Lecco Hospital, Lecco, Italy.
Kidney Int. 2000 Nov;58(5):2194-9. doi: 10.1111/j.1523-1755.2000.00393.x.
The aim of this study was to investigate the effect of pH and glucose concentration on sodium removal and the dialysate and plasma sodium ratio (D/PNa) as measured by means of a flame photometer (NaF) or direct ion-selective electrode (NaE) in continuous ambulatory peritoneal dialysis (CAPD).
In vitro, glucose concentration, pH, NaF, and NaE were measured in fresh peritoneal dialysis solutions (PDSs) before and after the addition of glucose or KOH. In vivo, 66 four-hour peritoneal equilibration tests were performed in 35 patients on CAPD using a low pH PDS with a glucose concentration of 3.86%.
In vitro, NaF and NaE were significantly influenced by the glucose concentration and pH of the PDS. In vivo, in fresh PDS, there was a significant difference between the NaF and NaE results; the respective median values were 132.1 (interquartile range 129.3 to 137.5) versus 138.0 (134.4 to 141.5) mmol/L (P < 0.0001). The D/PNa ratio calculated by NaE was significantly lower than that calculated by NaF (0.88 +/- 0.03 vs. 0.91 +/- 0.04 and 0. 90 +/- 0.03 vs. 0.94 +/- 0.04 at 60 and 240 min, respectively, P < 0.0001), whereas there was no significant difference between the NaE and NaF values after correction for plasma water and a Donnan factor of 0.96 (0.88 +/- 0.03 vs. 0.88 +/- 0.04 and 0.90 +/- 0.03 vs. 0.91 +/- 0.04, P < 0.3473). Sodium removal was significantly lower when calculated as NaE than when calculated as NaF (43.9 +/- 32.7 vs. 61.0 +/- 32.2 mmol, P < 0.0001).
The fresh PDS sodium concentration can be corrected using a glucose concentration-related factor. The D/PNa ratio calculated as NaE or NaF is not different after correction for plasma water and a Donnan factor of 0.96. Sodium removal must be measured by means of NaF rather than NaE. This could have an important clinical impact.
本研究旨在探讨pH值和葡萄糖浓度对持续性非卧床腹膜透析（CAPD）中钠清除及通过火焰光度计（NaF）或直接离子选择电极（NaE）测得的透析液与血浆钠比值（D/PNa）的影响。
在体外，于添加葡萄糖或氢氧化钾前后，对新鲜腹膜透析液（PDS）中的葡萄糖浓度、pH值、NaF和NaE进行测量。在体内，对35例接受CAPD治疗的患者使用葡萄糖浓度为3.86%的低pH值PDS进行了66次4小时的腹膜平衡试验。
在体外，NaF和NaE受PDS的葡萄糖浓度和pH值的显著影响。在体内，新鲜PDS中，NaF和NaE的结果存在显著差异；各自的中位数分别为132.1（四分位间距129.3至137.5）与138.0（134.4至141.5）mmol/L（P < 0.0001）。由NaE计算得出的D/PNa比值显著低于由NaF计算得出的比值（分别在60分钟和240分钟时为0.88±0.03对0.91±0.04以及0.90±0.03对0.94±0.04，P < 0.0001），然而在校正血浆水和Donnan因子0.96后，NaE和NaF的值之间无显著差异（0.88±0.03对0.88±0.04以及0.90±0.03对0.91±0.04，P < 0.3473）。以NaE计算的钠清除显著低于以NaF计算的钠清除（43.9±32.7对61.0±32.2 mmol，P < 0.0001）。
新鲜PDS钠浓度可用与葡萄糖浓度相关的因子进行校正。在校正血浆水和Donnan因子0.96后，以NaE或NaF计算的D/PNa比值无差异。必须通过NaF而非NaE来测量钠清除。这可能会产生重要的临床影响。
