title: Optimal convection volume for improving patient outcomes in an international incident dialysis cohort treated with online hemodiafiltration.
abstract: Online hemodiafiltration (OL-HDF), the most efficient renal replacement therapy, enables enhanced removal of small and large uremic toxins by combining diffusive and convective solute transport. Randomized controlled trials on prevalent chronic kidney disease (CKD) patients showed improved patient survival with high-volume OL-HDF, underlining the effect of convection volume (CV). This retrospective international study was conducted in a large cohort of incident CKD patients to determine the CV threshold and range associated with survival advantage. Data were extracted from a cohort of adult CKD patients treated by post-dilution OL-HDF over a 101-month period. In total, 2293 patients with a minimum of 2 years of follow-up were analyzed using advanced statistical tools, including cubic spline analyses for determination of the CV range over which a survival increase was observed. The relative survival rate of OL-HDF patients, adjusted for age, gender, comorbidities, vascular access, albumin, C-reactive protein, and dialysis dose, was found to increase at about 55 l/week of CV and to stay increased up to about 75 l/week. Similar analysis of pre-dialysis β2-microglobin (marker of middle-molecule uremic toxins) concentrations found a nearly linear decrease in marker concentration as CV increased from 40 to 75 l/week. Analysis of log C-reactive protein levels showed a decrease over the same CV range. Thus, a convection dose target based on convection volume should be considered and needs to be confirmed by prospective trials as a new determinant of dialysis adequacy.
authors.affiliation: Montpellier University I, UFR Medicine, Montpellier, France.|Fresenius Medical Care, Bad Homburg, Germany.
authors.forename: Bernard
authors.initials: B
authors.lastname: Canaud
authors.affiliation: Fresenius Medical Care, Bad Homburg, Germany.
authors.forename: Carlo
authors.initials: C
authors.lastname: Barbieri
authors.affiliation: Fresenius Medical Care, Bad Homburg, Germany.|Danube University, Krems, Austria.
authors.forename: Daniele
authors.initials: D
authors.lastname: Marcelli
authors.affiliation: Fresenius Medical Care, Bad Homburg, Germany.
authors.forename: Francesco
authors.initials: F
authors.lastname: Bellocchio
authors.affiliation: Fresenius Medical Care, Bad Homburg, Germany.
authors.forename: Sudhir
authors.initials: S
authors.lastname: Bowry
authors.affiliation: Fresenius Medical Care, Bad Homburg, Germany.
authors.forename: Flavio
authors.initials: F
authors.lastname: Mari
authors.affiliation: Fresenius Medical Care, Bad Homburg, Germany.
authors.forename: Claudia
authors.initials: C
authors.lastname: Amato
authors.affiliation: Fresenius Medical Care, Bad Homburg, Germany.|Danube University, Krems, Austria.
authors.forename: Emanuele
authors.initials: E
authors.lastname: Gatti
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002097:C-Reactive Protein / Q000378:metabolism; D015314:Dialysis Solutions / Q000008:administration & dosage*; D005260:Female; D005500:Follow-Up Studies; D017583:Hemodiafiltration / Q000379:methods*; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood / Q000401:mortality / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome; D001613:beta 2-Microglobulin / Q000097:blood
chemical_list: D015314:Dialysis Solutions; D001613:beta 2-Microglobulin; D002097:C-Reactive Protein