Citrate Dialysate in Online Hemodialfiltration
Condition: Hemodiafiltration; Heparin; Haemodialysis; Citrate Reaction
Study type: Interventional

Summary: 
      Online hemodiafiltration (Ol-HDF) is increasingly being used for patients on chronic dialysis
      due to in its superiority compared with standard hemodialysis HDF. In addition to an
      excellent clearance of small molecules, oL-HDF has more advantages by providing both
      diffusion and convection modalities for an additional clearance of medium-size molecules.
      Furthermore, OL-HDF has been associated with not only better hemodynamic tolerance and
      biocompatibility , but may even include better survival.with reduction of proinflammatory
      cytokines and proinflammatory circulating cells , as well as with better control of B2MG
      levels .Ol-HDF is classified into 2 types according to the mode of addition of the
      substitution fluid: pre-dilution OL-HDF (pre-HDF) and post-dilution OL-HDF (post-HDF);
      Post-HDF was associated with significantly higher removal rates of β2-MG than HD.
      Postdilution HDF is the most effective way to maximize molecule clearance .Post-HDF was
      associated with significantly higher removal rate of α1-MG, and also significantly higher
      albumin leakage, than HD and pre-HDF. However, blood concentrations can be elevated using
      HDF, which can cause thrombosis. On the other hand, predilution HDF can resolve this problem
      but requires about three times more purified water than postdilution HDF and may not elicit
      maximal clearance.
    

Detailed description: 
      Heparin is the most routinely used anticoagulant in hemodialysis. However, it exposes the
      patient to the risk of bleeding complications and can induce thrombocytopenia. Furthermore,
      long-term use of heparin induces biological and clinical complications (osteoporosis,
      dyslipidemia, hyperkalemia) . Regional citrate anticoagulation is a good alternative to
      heparin use in hemodialysis for patients with increased bleeding risk , but its
      implementation in bicarbonate hemodialysis (BHD) is laborious and cumbersome: severe side
      effects can occur due to citrate metabolism and difficulties in adaptation of calcium
      infusion into the venous line .Therefore, the use of citrate as a dialysis buffer instead of
      acetate has proven a safe alternative to acetate-containing bicarbonate dialysis and on-line
      hemodiafiltration without significant hypocalcemia or clinically important coagulation
      issues.The aim of the present study is the comparison of the patency of the dialyzer ,the
      quality of life and blood parameters between pre and potdiltuiotn Ol-HDF with citrate
      dialysate (CD). No study to date has previously compared the use of citrate dialysate between
      these two modalities in oL-HDF.
    

Intervention name(s): Pre-dilution online hemodiafiltration with citrate dialysate; Post-dilution hemodiafiltration with citrate dialysate
Intervention type(s): Procedure; Procedure
Intervention description(s): After enrollment, all patients began a 2-week run-in period with conventional dialysis fluid containing acetate and the lowest dose of unfractionated heparin. The investigator titrated the heparin dose by reducing the dose step by step, 25% in each step, until the final minimal dose was achieved. The experimental study consisted of 3 phases, 4 weeks in each phase, and the phases were separated by 1-week washout periods. Phase 1 used CD with 50% of the heparin dose of the baseline. Phases 2 and 3 used 25% heparin and no heparin, respectively. New dialyzers were introduced at the beginning of each phase and the heparin dose was resumed during the washout phase. The calcium concentration in the dialysis fluid was kept constant (1.5 mmol/L) to allow evaluation of the effect of CD on calcium balance; same protocol with post-dilution Ol-HDF in these same patients for the later 12 weeks.
Intervention MeSH terms: Citric Acid; Sodium Citrate; Dialysis Solutions
Intervention model: Single Group Assignment
Intervention model description: One group interrupted times-series design (ITS)
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: online hemodialfiltration; hemodialysis; citrate; adequacy of dialysis; heparin