Zhang Weichen, Du Qiuna, Xiao Jing, Bi Zhaori, Yu Chen, Ye Zhibin, Wang Mengjing, Chen Jing
Nephrology, Huashan Hospital, Fudan University, Shanghai, China.
Nephrology, Tongji Hospital, Tongji University, Shanghai, China.
Kidney Blood Press Res. 2021;46(1):53-62. doi: 10.1159/000511375. Epub 2021 Jan 21.
Our research group has previously reported a noninvasive model that estimates phosphate removal within a 4-h hemodialysis (HD) treatment. The aim of this study was to modify the original model and validate the accuracy of the new model of phosphate removal for HD and hemodiafiltration (HDF) treatment.
A total of 109 HD patients from 3 HD centers were enrolled. The actual phosphate removal amount was calculated using the area under the dialysate phosphate concentration time curve. Model modification was executed using second-order multivariable polynomial regression analysis to obtain a new parameter for dialyzer phosphate clearance. Bias, precision, and accuracy were measured in the internal and external validation to determine the performance of the modified model.
Mean age of the enrolled patients was 63 ± 12 years, and 67 (61.5%) were male. Phosphate removal was 19.06 ± 8.12 mmol and 17.38 ± 6.75 mmol in 4-h HD and HDF treatments, respectively, with no significant difference. The modified phosphate removal model was expressed as Tpo4 = 80.3 × C45 - 0.024 × age + 0.07 × weight + β × clearance - 8.14 (β = 6.231 × 10-3 × clearance - 1.886 × 10-5 × clearance2 - 0.467), where C45 was the phosphate concentration in the spent dialysate measured at the 45th minute of HD and clearance was the phosphate clearance of the dialyzer. Internal validation indicated that the new model was superior to the original model with a significantly smaller bias and higher accuracy. External validation showed that R2, bias, and accuracy were not significantly different than those of internal validation.
A new model was generated to quantify phosphate removal by 4-h HD and HDF with a dialyzer surface area of 1.3-1.8 m2. This modified model would contribute to the evaluation of phosphate balance and individualized therapy of hyperphosphatemia.
我们的研究小组之前报告了一种非侵入性模型，该模型可估计4小时血液透析（HD）治疗过程中的磷清除情况。本研究的目的是修改原始模型，并验证用于HD和血液透析滤过（HDF）治疗的磷清除新模型的准确性。
招募了来自3个HD中心的109例HD患者。使用透析液磷浓度时间曲线下的面积计算实际磷清除量。采用二阶多变量多项式回归分析进行模型修改，以获得透析器磷清除率的新参数。在内部和外部验证中测量偏差、精密度和准确性，以确定修改后模型的性能。
入组患者的平均年龄为63±12岁，其中67例（61.5%）为男性。在4小时的HD和HDF治疗中，磷清除量分别为19.06±8.12 mmol和17.38±6.75 mmol，无显著差异。修改后的磷清除模型表示为Tpo4 = 80.3×C45 - 0.024×年龄 + 0.07×体重 + β×清除率 - 8.14（β = 6.231×10-3×清除率 - 1.886×10-5×清除率2 - 0.467），其中C45是HD第45分钟时测量的用过透析液中的磷浓度，清除率是透析器的磷清除率。内部验证表明，新模型优于原始模型，偏差显著更小，准确性更高。外部验证表明，R2、偏差和准确性与内部验证无显著差异。
生成了一个新模型，用于量化透析器表面积为1.3 - 1.8 m2的4小时HD和HDF的磷清除情况。这个修改后的模型将有助于评估磷平衡和高磷血症的个体化治疗。
