背景:腹膜透析停留时间之间的残留量变化会在超滤测定中产生不确定性,透析效率,如果剩余体积较大,则存在过度填充的风险。在流体填充过程中测量标记分子的稀释提供了一种方便的方法。然而,估计的准确性取决于稀释标记的选择。与基于白蛋白的残余体积和三孔模型估计相比,我们在这里评估肌酐和尿素作为稀释标志物的可行性。
方法:本临床,回顾性分析包括来自20个人的56个剩余体积估计值,基于预填充透析液肌酐的稀释,透析液填充阶段的尿素和白蛋白浓度。结果分别进行了比较。超滤诱导的偏差,使用三孔模型量化了标记分子的传质和液体葡萄糖含量的影响。线性回归建立了能够在各种标记分子之间进行转换的转换因子。
结果:基于肌酐的计算在1.5%的dwell中高估了115mL(IQR89-149),在4.25%的葡萄糖dwell中高估了252mL(IQR-313)。在高渗住宅中,超滤52毫升(IQR38-66),而腹膜内肌酐在充液过程中增加了67%,是高估的主要原因。基于白蛋白的体积与三孔模型估计值非常吻合。校正因子有效地实现了标记分子的互换性。
结论:低分子量标记分子的传质与残余体积高估有关。然而,通过应用校正因子,肌酐和尿素稀释仍然可以提供合理的估计,特别是当目的是排除存在非常大的剩余体积时。
BACKGROUND: Variation in residual volume between peritoneal dialysis dwells creates uncertainty in ultrafiltration determination, dialysis efficiency, and poses a risk of overfill if the residual volume is large. Measuring the dilution of a marker molecule during fluid fill offers a convenient approach, however, estimation accuracy depends on the choice of dilution marker. We here evaluate the feasibility of creatinine and urea as dilution markers compared to albumin-based residual volumes and three-pore model estimations.
METHODS: This clinical, retrospective analysis comprises 56 residual volume estimations from 20 individuals, based on the dilution of pre-fill dialysate creatinine, urea and albumin concentrations during the dialysis fluid fill phase. Outcomes were compared individually. Bias induced by ultrafiltration, marker molecule mass-transfer and influence of fluid glucose contents was quantified using the three-pore model. Linear regression established conversion factors enabling conversion between the various marker molecules.
RESULTS: Creatinine-based calculations overestimated residual volumes by 115 mL (IQR 89-149) in 1.5% dwells and 252 mL (IQR 179-313) in 4.25% glucose dwells. In hypertonic dwells, ultrafiltration was 52 mL (IQR 38-66), while intraperitoneal creatinine mass increased by 67% during fluid fill, being the leading cause of overestimation. Albumin-based volumes conformed strongly with three-pore model estimates. Correction factors effectively enabled marker molecule interchangeability.
CONCLUSIONS: Mass-transfer of low molecular weight marker molecules is associated with residual volume overestimation. However, by applying correction factors, creatinine and urea dilution can still provide reasonable estimates, particularly when the purpose is to exclude the presence of a very large residual volume.