title: Internal hemodiafiltration versus low-flux bicarbonate dialysis: Results from a long-term prospective study.
abstract: BACKGROUND
  About ten years ago it was discovered that changes in filter design which increase passive filtration improved dialysis efficiency. Later, these modified membranes showed similar intra-dialytic efficiency when used in on-line hemodiafiltration or in bicarbonate dialysis, called internal hemodiafiltration.
  
  
  OBJECTIVE
  On the basis of these previous results, we studied the long-term effects of internal hemodiafiltration, in comparison with low-flux bicarbonate dialysis. The pre-dialysis beta2-microglobulin level was chosen as the primary outcome variable. A prospective multicenter study with a cross-over scheme, 2 treatments and 3 periods, was designed. Twenty-four patients, followed in two dialysis centers, were enrolled. Many other parameters were measured every month at the first dialysis session of the week. The intra-dialytic removal of urea, beta2-microglobulin and homocysteine was also calculated.
  
  
  RESULTS
  The removal of uremic toxins was significantly higher in internal hemodiafiltration than in low-flux bicarbonate dialysis. The pre-dialysis value of urea, phosphorus, beta2-microglobulin and homocysteine was lower during internal hemodiafiltration as compared with low-flux bicarbonate dialysis. The mean pre-dialysis value of hemoglobin was significantly higher during internal hemodiafiltration than low-flux bicarbonate dialysis, with a trend towards a significantly lower consumption of erythropoiesis stimulating agents during internal hemodiafiltration as compared with low-flux bicarbonate dialysis.
  
  
  CONCLUSIONS
  Long-term treatment with internal hemodiafiltration improves the removal of small molecules and stops the continuous increase of middle molecules as seen in low-flux bicarbonate dialysis. Internal hemodiafiltration may substitute low-flux bicarbonate dialysis, but we need new prospective studies about long-term hard end-points.
authors.affiliation: Nephrology and Dialysis Unit, Vimercate Hospital, Vimercate, Italy. righettim@hotmail.com
authors.forename: Marco
authors.initials: M
authors.lastname: Righetti
authors.forename: Oliviero
authors.initials: O
authors.lastname: Filiberti
authors.forename: Andrea
authors.initials: A
authors.lastname: Ranghino
authors.forename: Gianmichele
authors.initials: G
authors.lastname: Ferrario
authors.forename: Silvana
authors.initials: S
authors.lastname: Milani
authors.forename: Paola
authors.initials: P
authors.lastname: Serbelloni
authors.forename: Gian Enrico
authors.initials: GE
authors.lastname: Guida
authors.forename: Adalberto
authors.initials: A
authors.lastname: Tommasi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001639:Bicarbonates / Q000737:chemistry / Q000627:therapeutic use*; D015415:Biomarkers / Q000097:blood; D016009:Chi-Square Distribution; D018592:Cross-Over Studies; D004867:Equipment Design; D005260:Female; D006397:Hematinics / Q000627:therapeutic use; D017583:Hemodiafiltration / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D015312:Hemodialysis Solutions / Q000737:chemistry / Q000627:therapeutic use*; D006454:Hemoglobins / Q000627:therapeutic use; D006710:Homocysteine / Q000097:blood; D006801:Humans; D007558:Italy; D008297:Male; D008567:Membranes, Artificial; D008875:Middle Aged; D011446:Prospective Studies; D013997:Time Factors; D016896:Treatment Outcome; D014508:Urea / Q000097:blood; D001613:beta 2-Microglobulin / Q000097:blood
chemical_list: D001639:Bicarbonates; D015415:Biomarkers; D006397:Hematinics; D015312:Hemodialysis Solutions; D006454:Hemoglobins; D008567:Membranes, Artificial; D001613:beta 2-Microglobulin; D006710:Homocysteine; D014508:Urea