Comparison of citrate dialysate in pre- and post-dilution online hemodiafiltration: effect on clot formation and adequacy of dialysis in hemodialysis patients.

Background: Citrate dialysate (CD) has been successfully used in conventional hemodialysis and continuous renal replacement therapy; however, no study has compared pre- and post-dilution online hemodiafiltration (oL-HDF). Therefore, we aimed to investigate the efficacy of citrate anticoagulation for oL-HDF and the metabolic changes and quality of life of patients on hemodialysis treated using both modes.

Method: Eight dialysis patients were treated with CD containing 0.8 mmol of citric acid for 4 weeks in each phase. Visual clotting scores were investigated as the primary endpoints. Adequacy of dialysis, laboratory parameters, and quality of life were measured as secondary objectives.

Results: The mean clotting scores in the pre-dilution mode were significantly lower than those in the post-dilution mode and in all phases except the heparin-free phase (p < 0.001 in the baseline phase, p = 0.001 in phase 1, and p = 0.023 in phase 2). The values of Kt/V in both modalities were comparable except during the baseline phase, in which the values of pre-dilution were significantly greater than post-dilution (2.36 ± 0.52/week vs. 1.87 ± 0.33/week;95% CI -0.81 to -0.19, p = 0.002). The patient's quality of life regarding their physical activity level was significantly higher in the post-dilution mode than in the pre-dilution mode at baseline and in phase 1 (p = 0.014 and 0.004 at baseline and in phase 1, respectively). Metabolic changes did not differ between the two modes.

Conclusion: Citrate dialysate decreased or prevented anticoagulation in both pre- and post-dilution modes of oL-HDF without significant side effects and had comparable adequacy of dialysis.