Consequences of increasing convection onto patient care and protein removal in hemodialysis.
BACKGROUND
Recent randomised controlled trials suggest that on-line hemodiafiltration (OL-HDF) improves survival, provided that it reaches high convective volumes. However, there is scant information on the feasibility and the consequences of modifying convection volumes in clinics.


METHODS
Twelve stable dialysis patients were treated with high-flux 1.8 m2 polysulphone dialyzers and 4 levels of convection flows (QUF) based on GKD-UF monitoring of the system, for 1 week each. The consequences on dialysis delivery (transmembrane pressure (TMP), number of alarms, % of achieved prescribed convection) and efficacy (mass removal of low and high molecular weight compounds) were analysed.


RESULTS
TMP increased exponentially with QUF (p<0.001 for N >56,000 monitoring values). Beyond 21 L/session, this resulted into frequent TMP alarms requiring nursing staff interventions (mean ± SEM: 10.3 ± 2.2 alarms per session, p<0.001 compared to lower convection volumes). Optimal convection volumes as assessed by GKD-UF-max were 20.6 ± 0.4 L/session, whilst 4 supplementary litres were obtained in the maximum situation (24.5 ± 0.6 L/session) but the proportion of sessions achieving the prescribed convection volume decreased from 94% to only 33% (p<0.001). Convection increased high molecular weight compound removal and shifted the membrane cut-off towards the higher molecular weight range.


CONCLUSIONS
Reaching high convection volumes as recommended by the recent RCTs (> 20L) is feasible by setting an HDF system at its optimal conditions based upon the GKD-UF monitoring. Prescribing higher convection volumes resulted in instability of the system, provoked alarms, was bothersome for the nursing staff and the patients, rarely achieved the prescribed convection volumes and increased removal of high molecular weight compounds, notably albumin.
RD-Néphrologie and EA7288, University of Montpellier, Montpellier, France.
Nathalie
N
Gayrard
RD-Néphrologie and EA7288, University of Montpellier, Montpellier, France.
Alain
A
Ficheux
RD-Néphrologie and EA7288, University of Montpellier, Montpellier, France.
Flore
F
Duranton
RD-Néphrologie and EA7288, University of Montpellier, Montpellier, France.
Caroline
C
Guzman
Centre de dialyse Néphrologie Dialyse St Guilhem, Sète, France.
Ilan
I
Szwarc
Centre de dialyse Néphrologie Dialyse St Guilhem, Sète, France.
Fernando
F
Vetromile
CoMET, INM Montpellier, NRI facilities, Montpellier, France.
Chantal
C
Cazevieille
Service de Néphrologie, Hôpital de La Conception-Université Aix-Marseille, Marseille, France.|European Uraemic Toxin Working Group of ESAO, endorsed by ERA-EDTA (EUTox), Krems, Austria.
Philippe
P
Brunet
Centre de dialyse Néphrologie Dialyse St Guilhem, Sète, France.
Marie-Françoise
MF
Servel
RD-Néphrologie and EA7288, University of Montpellier, Montpellier, France.|Centre de dialyse Néphrologie Dialyse St Guilhem, Sète, France.|European Uraemic Toxin Working Group of ESAO, endorsed by ERA-EDTA (EUTox), Krems, Austria.
Àngel
http://orcid.org/0000-0001-7029-4532
À
Argilés
Service de Néphrologie et Transplantation, Hôpital Lapeyronie CHU Montpellier, Montpellier, France.
Moglie
M
Le Quintrec
D000368:Aged; D000369:Aged, 80 and over; D001798:Blood Proteins; D018481:Convection; D015314:Dialysis Solutions; D005260:Female; D017583:Hemodiafiltration / Q000009:adverse effects / Q000379:methods; D006801:Humans; D008297:Male; D008567:Membranes, Artificial; D008875:Middle Aged; D009997:Osmotic Pressure; D005791:Patient Care; D006435:Renal Dialysis / Q000009:adverse effects / Q000379:methods
D001798:Blood Proteins; D015314:Dialysis Solutions; D008567:Membranes, Artificial