Evaluation of Hygiene and Safety Controls for On-Line Paired Hemodiafiltration (PHF)

Abstract

Background On-line hemodiafiltration is gaining popularity due to increasing evidence of clinical benefits however it also requires strict attention to hygiene and safety as notable quantities of liquid are reinfused into the patient. Although most centers are improving their attention to water quality, a frequent concern is the inadvertent or accidental contamination of water and whether the redundant safety controls are sufficient to protect the patient. In the present study, in order to simulate a worst-case safety condition, we tested in vitro the reliability of paired hemodiafiltration – (PHF), under low, moderate and high bacterial contamination of the water supply. Tests were performed using various bacterial concentrations (range 85–2000 cfu/mL) of Pseudomonas Aeruginosa. Samples were analyzed from different sites throughout the entire on-line hemodiafiltration circuit for bacteria endotoxin, fungus and ability to stimulate whole blood production of TNF α. Results In the in vitro contamination study, with the three bacterial concentrations tested at various points of the circuit, bacteria were below the level of detection and endotoxins were < 0.01 UE/mL. Addition of dialysate samples taken after the first stage of microfiltration, as well as after the first and second stage of ultrafiltration and incubated with whole blood were not associated with stimulated production of TNFα. Conclusions PHF appeared to be a safe and feasible method for on-line hemodiafiltration even in the unforeseen presence of bacterial contamination of the feed water or water distribution system.

Quantitative analysis of convective dose in hemofiltration and hemodiafiltration: “Predilution” vs. “postdilution” reinfusion

“…A longer than 15‐year experience with high‐volume HDF has not so far disclosed any specific treatment‐related adverse consequences 2 . The microbiological purity of online generated reinfusate has been shown to be at least as good as commercial sterile solutions for infusion 13 . Moreover, the issue of possible substance depletion has not yet been specifically addressed.…”

Convection‐enhanced High‐Flux Hemodialysis

“…In addition, although high-flux hemodialysis with increased filtration provides a simple but efficient method of treating renal failure patients, caution should be exercised concerning dialysate quality (17), as pyrogen transferred from dialysate to the blood stream can cause unpleasant and sometimes serious side effects. Thus, the water treatment circuit used to prepare ultrapure dialysate should be equipped with a barrier that excludes the possibility of pyrogen transfer.…”

Hemodiafiltration: Evolution of a Technique towards Better Dialysis Care

“…2g) the ultrafiltrate produced is purified by adsorption through a resin/charcoal unit and utilized subsequently as a replacement fluid. In PFD with exogenous reinfusion, the first unit is used to backfilter some fresh dialysate which then acts as ultrapure online filtered replacement fluid [7].…”