Clinical and Academic Unit of Nephrology, Hospital Universitário Pedro Ernesto, Rio de Janeiro State University (UERJ), Rio de Janeiro, Brazil.
Am J Nephrol. 2012;36(2):121-6. doi: 10.1159/000338675. Epub 2012 Jul 7.
The control of hyperphosphatemia is an unmet need in dialysis care. Compared to conventional hemodialysis (cHD), extended hemodialysis (eHD) appears to more easily control blood phosphate levels in chronically dialyzed patients. Here, we sought to compare eKT/V-matched cHD and eHD procedures in order to quantify the contribution of dialysis prescription and time in the mass removal of phosphate.
Eight stable hemodialysis patients with negligible residual renal function underwent cHD and eHD sessions adjusted to provide the same eKT/V(urea). Total dialysate, total and hourly partial dialysate and blood samples were collected for comparison of mass extraction of urea, creatinine, and phosphate.
Mean eKT/V(urea) was similar in eHD and cHD (1.30 vs. 1.28, p = nonsignificant). Likewise, mass removal of urea and creatinine during cHD and eHD were not significantly different. Conversely, phosphate mass removal was 40% higher with eHD as compared to cHD (1,219 ± 262 vs. 858 ± 186 mg, p = 0.015). Although hourly mass removal of phosphate was higher during cHD, the prolonged period of lesser but continuous removal was responsible for higher total phosphate elimination during eHD.
In dialysis sessions matched to provide a similar eKT/V(urea), removal of phosphate increases by 40% when time is extended from 4 to 8 h. Urea-based adequacy models cannot be used to predict the amount of phosphorus removal during hemodialysis.
控制高磷血症是透析治疗中的一个未满足的需求。与传统血液透析（cHD）相比，延长血液透析（eHD）似乎更能轻易地控制慢性透析患者的血磷水平。在此，我们旨在比较 eKT/V 匹配的 cHD 和 eHD 程序，以量化透析方案和时间对磷酸盐质量去除的贡献。
8 名稳定的血液透析患者几乎没有残余肾功能，他们接受了 cHD 和 eHD 治疗，调整后的方案可提供相同的 eKT/V（尿素）。收集总透析液、总部分透析液和每小时部分透析液以及血液样本，以比较尿素、肌酐和磷酸盐的质量提取。
eHD 和 cHD 的平均 eKT/V（尿素）相似（1.30 对 1.28，p=无显著性差异）。同样，cHD 和 eHD 期间尿素和肌酐的质量去除也无显著差异。相反，与 cHD 相比，eHD 时磷酸盐的质量去除增加了 40%（1,219 ± 262 对 858 ± 186 mg，p=0.015）。尽管 cHD 期间磷酸盐的每小时质量去除较高，但由于延长了时间，连续去除的时间较短，但总磷酸盐的去除量仍较高。
在提供相似 eKT/V（尿素）的透析治疗中，将时间从 4 小时延长至 8 小时可使磷酸盐的去除量增加 40%。基于尿素的充分性模型不能用于预测血液透析期间磷的去除量。
