Clinical Research Branch, Division of Nephrology, Miulli General Hospital, Acquaviva delle Fonti, Italy.
Dialysis Centre SM2, Potenza, Italy.
Nephrol Dial Transplant. 2018 Jul 1;33(7):1103-1109. doi: 10.1093/ndt/gfx225.
Most people who make the transition to maintenance haemodialysis (HD) therapy are treated with a fixed dose of thrice-weekly HD (3HD/week) regimen without consideration of their residual kidney function (RKF). The RKF provides an effective and naturally continuous clearance of both small and middle molecules, plays a major role in metabolic homeostasis, nutritional status and cardiovascular health, and aids in fluid management. The RKF is associated with better patient survival and greater health-related quality of life. Its preservation is instrumental to the prescription of incremental (1HD/week to 2HD/week) HD. The recently heightened interest in incremental HD has been hindered by the current limitations of the urea kinetic model (UKM), which tend to overestimate the needed dialysis dose in the presence of a substantial RKF. A recent paper by Casino and Basile suggested a variable target model (VTM), which gives more clinical weight to the RKF and allows less frequent HD treatments at lower RKF as opposed to the fixed target model, based on the wrong concept of the clinical equivalence between renal and dialysis clearance. A randomized controlled trial (RCT) enrolling incident patients and comparing incremental HD (prescribed according to the VTM) with the standard 3HD/week schedule and focused on hard outcomes, such as survival and health-related quality of life of patients, is urgently needed. The first step in designing such a study is to compute the 'adequacy lines' and the associated fitting equations necessary for the most appropriate allocation of the patients in the two arms and their correct and safe follow-up. In conclusion, the potentially important clinical and financial implications of the incremental HD render it highly promising and warrant RCTs. The UKM is the keystone for conducting such studies.
大多数接受维持性血液透析（HD）治疗的患者均接受每周 3 次的固定剂量透析方案（3HD/周），而不考虑其残余肾功能（RKF）。RKF 可有效且持续清除小分子和中分子物质，在代谢平衡、营养状况和心血管健康方面发挥着重要作用，并有助于液体管理。RKF 与更好的患者生存率和更高的健康相关生活质量相关。保留 RKF 对于递增式（每周增加 1 次至 2 次 HD）HD 的处方至关重要。最近，人们对递增式 HD 的兴趣日益浓厚，但受到尿素动力学模型（UKM）的当前局限性的阻碍，在存在大量 RKF 的情况下，UKM 往往会高估所需的透析剂量。最近，Casino 和 Basile 的一篇论文提出了可变目标模型（VTM），该模型更重视 RKF，并允许在较低的 RKF 下进行较少的 HD 治疗，而不是基于肾清除率和透析清除率之间临床等效性的错误概念的固定目标模型。急需一项纳入新发病例患者的随机对照试验（RCT），比较递增式 HD（根据 VTM 处方）与标准的 3HD/周方案，并重点关注生存和患者健康相关生活质量等硬结局。设计此类研究的第一步是计算“充足线”及其相关拟合方程，以最适当地将患者分配到两个治疗组中，并对其进行正确和安全的随访。总之，递增式 HD 具有潜在的重要临床和经济意义，因此非常有前景，值得进行 RCT。UKM 是开展此类研究的关键。
