Department of Clinical Sciences Lund, Skåne University Hospital, Lund, Sweden.
Division of Nephrology, Cliniques universitaires Saint-Luc, Brussels, Belgium.
Kidney360. 2024 Feb 1;5(2):195-204. doi: 10.34067/KID.0000000000000358. Epub 2024 Jan 18.
Ultrafiltration (UF) is a key component of clinical peritoneal dialysis prescription, but the traditional method to assess UF is hampered by large inaccuracies. Here we propose a novel method, based on a computational model and on a single dialysate sodium measurement, to accurately estimate UF and osmotic conductance to glucose in patients on peritoneal dialysis.
Volume overload is highly prevalent among patients treated with peritoneal dialysis (PD), contributes to hypertension, and is associated with an increased risk of cardiovascular events and death in this population. As a result, optimizing peritoneal ultrafiltration (UF) is a key component of high-quality dialysis prescription. Osmotic conductance to glucose (OCG) reflects the water transport properties of the peritoneum, but measuring it requires an accurate quantification of UF, which is often difficult to obtain because of variability in catheter patency and peritoneal residual volume.
In this study, we derived a new mathematical model for estimating UF during PD, on the basis of sodium sieving, using a single measure of dialysate sodium concentration. The model was validated experimentally in a rat model of PD, using dialysis fluid with two different sodium concentrations (125 and 134 mmol/L) and three glucose strengths (1.5%, 2.3%, and 4.25%). Then, the same model was tested in a cohort of PD patients to predict UF.
In experimental and clinical conditions, the sodium-based estimation of UF rate correlated with UF rate measurements on the basis of volumetry and albumin dilution, with a =0.35 and =0.76, respectively. UF on the basis of sodium sieving was also successfully used to calculate OCG in the clinical cohort, with a Pearson of 0.77.
Using the novel mathematical models in this study, the sodium dip can be used to accurately estimate OCG, and therefore, it is a promising measurement method for future clinical use.
超滤（UF）是临床腹膜透析处方的关键组成部分，但传统的 UF 评估方法存在较大误差。在这里，我们提出了一种新的方法，该方法基于计算模型和单次透析液钠测量值，以准确评估腹膜透析患者的 UF 和葡萄糖渗透压传导系数。
在接受腹膜透析（PD）治疗的患者中，容量超负荷非常普遍，会导致高血压，并使该人群发生心血管事件和死亡的风险增加。因此，优化腹膜超滤（UF）是高质量透析处方的关键组成部分。葡萄糖渗透压传导系数（OCG）反映了腹膜的水转运特性，但要测量它，需要准确量化 UF，由于导管通畅性和腹膜残留量的变化，UF 往往难以获得。
在这项研究中，我们基于钠筛，使用单次透析液钠浓度测量值，为 PD 期间 UF 估计导出了一个新的数学模型。该模型在 PD 大鼠模型中进行了实验验证，使用两种不同钠浓度（125 和 134 mmol/L）和三种葡萄糖浓度（1.5%、2.3%和 4.25%）的透析液。然后，在 PD 患者队列中测试了相同的模型来预测 UF。
在实验和临床条件下，基于钠的 UF 速率估计与基于体积测量和白蛋白稀释的 UF 速率测量相关，相关系数分别为 a=0.35 和 =0.76。基于钠筛的 UF 也成功用于计算临床队列中的 OCG，Pearson 相关系数为 0.77。
使用本研究中的新数学模型，可以使用钠差值准确估计 OCG，因此，它是一种有前途的未来临床应用的测量方法。
