The Eternal (Nocturnal) Quest for Better Dialysis Outcomes

Abstract

AS, Faul C, Sever S, Reiser J: CD2AP in mouse and human podocytes controls a proteolytic program that regulates cytoskeletal structure and cellular survival. J Clin Invest 121: 3965-3980, 2011 13. Jarad G, Miner JH: Albuminuria, wherefore art thou? J Am Soc Twenty years ago, Bernard Charra and colleagues from Tassin, France, published a seminal paper on the survival rate of patients undergoing thrice weekly 8-hour in-center hemodialysis (HD) treatments. 1 This publication, which still represents the gold standard for outcome in thrice weekly dialysis regimens, induced a global search for improved dialysis regimens leading to better outcomes. Twenty years, millions of dollars, and a multitude of clinical studies later, the quest for improved dialysis outcomes is still ongoing.The first decade since 1992 was mainly Kt/V-oriented, with clinical studies trying to define an optimum dialysis dose with respect to the diffusive elimination of small watersoluble uremic compounds. Eventually, the HEMO study, a randomized controlled trial comparing sessional target Kt/Vs of 1.20 and 1.45, put an end to this discussion by demonstrating in thrice weekly conventional HD that increasing sessional target Kt/V beyond 1.2 did not improve survival further.2 Recognition of these obvious limitations of a urea-centered dialysis world led to renewed interest in the removal of other potentially relevant azotemic toxins such as b-2-microglobulin, phosphate, and middle molecules.At the beginning of the second decade after Tassin, the research focus shifted toward convection, dialysis length, and treatment frequency. Several randomized controlled studies comparing hemodiafiltration (HDF) with conventional low or high-flux HD were initiated, which have either recently been completed or are still ongoing. Data from two of those studies, the Dutch Convective Transport Study and a Turkish study, have been presented in oral or abstract form in 2011, indicating that increasing convection by thrice weekly 3-to 5-hour on-line HDF had no significant effect on the outcome of dialysis patients.At the same time, there was an accumulation of encouraging data from small controlled or larger observational studies on the positive effects of more intense dialysis regimens on patient satisfaction and outcome. To answer the crucial question, whether the outcome of dialysis patients is significantly improved by maximally increasing dialysis dose and frequency, the two-armed Frequent Hemodialysis Network (FHN) Study was initiated. The first arm of the study examined the effect of short daily in-center HD compared with conventional thrice weekly HD over a 12-month period and had a positive result with the two primary endpoints, mortality or increase in left ventricular mass, and mortality or decrease in physical health composite score, being significantly lower in the more frequent HD group. 3 The second arm was designed to examine the effect of daily nocturnal, 6-to 8-hour home HD compared with conventional thrice weekly home HD. Although in the nocturnal FHN...

Dialysis frequency versus dialysis time, that is the question

“…Thus, these three retrospective cohort studies and the accompanying editorials concluded that there is a strong association between longer HD TT (at a minimum frequency of three times per week) and improved survival. 20,21…”