High-volume online haemodiafiltration treatment and outcome of end-stage renal disease patients: more than one mode

Abstract

The reduction of the dismally high mortality of current end-stage renal disease patients maintained on conventional standard haemodialysis (HD) remains an unmet medical need. Online haemodiafiltration (HDF) modes with various sites of fluid substitution (post-, pre-, mixed-and mid-dilution) are increasingly used worldwide as promising alternatives to conventional HD. Large scale cohort studies, post hoc analyses of randomized trials, and individual participant meta-analyses suggest that post-dilution and pre-dilution, especially with high substitution volumes, improve outcomes compared with conventional standard HD. However, there is no definitive proof of a survival advantage of HDF over standard HD. The different modes of high-volume HDF should be considered a therapeutic platform allowing to personalize and tailor routine HDF treatment. The selection of the HDF mode should be made according to individual patient characteristics. Utilizing high retention onset membranes, expanded haemodialysis (HDx) can achieve the same solute removal performance as HDF. Subgroups of high-volume OL-HDF patients could benefit from HDx. Ongoing and future trials should provide definitive proof for the superiority of high-volume OL-HDF over conventional HD or HDx to give guidance for the most favourable mode of dialytic therapy for clinical use.

Stepwise achievement of high convection volume in post‐dilution hemodiafiltration: A prospective observational study

“…Improved intradialytic blood pressure stability was reported in a previous study, 5 which may contribute to the beneficial effect of high‐volume post‐dilution HDF on survival. High‐volume HDF improves outcomes, especially in patients who are younger, need long‐term dialysis, have symptoms of uremia, and present with multiple complications during HD (nausea, vomiting, cramping, fatigue, and intradialytic hypotension) 8 …”

“…Treatment‐related parameters such as treatment time, dialyzer type, needle type, and BFR, rather than patient characteristics such as comorbidities and biochemical parameters, determine the magnitude of the convection volume 7,10 . The longer the treatment time and the higher the filtration fraction, the greater the convection volume 8,16 . Successful high‐volume post‐dilution HDF depends on high BFR (≥350 ml/min), an excellent vascular excess (arteriovenous fistula BFR ≥ 600 ml/min), the ability to achieve adequate anticoagulation throughout the HDF session, and the absence of any clinical disorder that increases blood viscosity 8 .…”

“…The longer the treatment time and the higher the filtration fraction, the greater the convection volume 8,16 . Successful high‐volume post‐dilution HDF depends on high BFR (≥350 ml/min), an excellent vascular excess (arteriovenous fistula BFR ≥ 600 ml/min), the ability to achieve adequate anticoagulation throughout the HDF session, and the absence of any clinical disorder that increases blood viscosity 8 . Currently, modifiable conditions for achieving an adequate prescription of high‐volume HDF are: access BFR 350–500 ml/min, dialysate flow rate 500 ml/min, infusion flow rate 90–160 ml/min, use of high‐flux membrane, and dialysis time ≥4 h 8,16 …”

“…Dialysis prescription factors include dialyzer type, needle size, blood flow rate (BFR), and treatment time 7 . Current recommendations on adequate dose of regular high‐volume post‐dilution HDF include a convection volume of ≥23 L/session or a substitution volume of ≥21 L/session, administered three times weekly 8,9 …”

Who is the winner, pre-, post-, or mixed-dilution hemodiafiltration?

“…However, the probabilities of clotting and protein deposition are increased when blood flow is interrupted. For that reason, a high blood flow rate (typically ≥350 mL/min) and a well-functioning vascular excess (arteriovenous fistula blood flow of ≥600 mL/min) are prerequisites for successful high-volume postdilution HDF [ 5 ].…”