Hemodiafiltration: Technical and Medical Insights

Despite the significant medical and technical improvements in the field of dialytic renal replacement modalities, morbidity and mortality are excessively high among patients with end-stage kidney disease, and most interventional studies yielded disappointing results. Hemodiafiltration, a dialysis method that was implemented in clinics many years ago and that combines the two main principles of hemodialysis and hemofiltration-diffusion and convection-has had a positive impact on mortality rates, especially when delivered in a high-volume mode as a surrogate for a high convective dose. The achievement of high substitution volumes during dialysis treatments does not only depend on patient characteristics but also on the dialyzer (membrane) and the adequately equipped hemodiafiltration machine. The present review article summarizes the technical aspects of online hemodiafiltration and discusses present and ongoing clinical studies with regards to hard clinical and patient-reported outcomes.

The effect of the anticoagulant on the cellular composition and growth factor content of platelet-rich plasma

BACKGROUND

The cellular and biochemical composition of the platelet rich plasma (PRP) may impact its regenerative capacity. PRP composition have been shown to vary substantially among different separation systems and protocols. The type and the dose of anticoagulant might affect the content of PRP.

OBJECTIVE

The objective of this study was to evaluate the effect of anticoagulant use, on cellular composition and the amount of growth factors in fresh PRP.

METHODS

Three different methods were used to prepare PRP from 12 healthy participants. The protocol 1 included standart dose sodium citrate (SC) (0.9 ml, 3.8%), protocol 2 included 0.5 ml SC and no anticoagulant was used in protocol 3. The PRP's were compared in regards to cellular content, capture efficiency of platelets (CE), concentrations and total doses of fresh studied vascular endothelial growth factor (VEGF), platelet derived growth factor -BB, (PDGF-BB), transforming growth factor β1 (TGF-β1) levels.

RESULTS

The CE and total platelet count were highest in protocol 1. The white blood cells (WBC) and VEGF were highest in protocol 3. The highest total TGF-β1 and total PDGF levels were obtained with protocol 1, while the highest total VEGF levels were obtained with protocol 3.

CONCLUSION

The results of this study revealed that the use and the dose of SC affects the cellular content of PRP and GFs measured in fresh PRP. The CE and platelet dose increases while the WBC and VEGF decreases with the use of SC.

Regional citrate anticoagulation in hemodialysis: an observational study of safety, efficacy, and effect on calcium balance during routine care

BACKGROUND

Regional citrate hemodialysis anticoagulation is used when heparin is contraindicated, but most protocols require large infusions of calcium and frequent intradialytic plasma ionized calcium measurements.

OBJECTIVES

The objective of this study was to determine the safety, efficacy, and effect on calcium balance of regional citrate anticoagulation using sparse plasma ionized calcium sampling.

DESIGN

The design of this study was observational.

SETTING

The setting of this study was the hospital hemodialysis center.

PATIENTS

The subjects of this study were the hospital hemodialysis patients.

MEASUREMENTS

Dialysate calcium concentration by atomic absorption spectroscopy and total dialysate weight were used as measurements.

METHODS

Regional citrate anticoagulation was introduced using zero calcium dialysate, pre-dialyzer citrate infusion, and post-dialyzer calcium infusion. Infusions were adjusted based on pre- and post-dialyzer calcium measurements obtained at least twice during a 4-h dialysis. The protocol was simplified after the first 357 sessions to dispense with post-dialyzer calcium measurements. Heparin-anticoagulated sessions were performed using acetate-acidified 1.25 mmol/L calcium or citrate-acidified 1.5 mmol/L calcium dialysate. Calcium balance assessment was by complete dialysate recovery. Safety and efficacy were assessed prospectively using a point-of-care database to record ionized calcium and clinical events. Groups were compared using t test, ANOVA, Wilcoxon rank sum, or Kruskal-Wallis as appropriate.

RESULTS

Seventy-five patients received regional citrate-anticoagulated dialysis over 1051 dialysis sessions. Of these, 357 dialysis sessions were performed using the original citrate anticoagulation protocol and 694 using the simplified protocol. Dialysis was effective and safe. Only 3 dialyzers clotted; 1 patient suffered symptomatic hypercalcemia and none suffered symptomatic hypocalcemia. Calcium balance was assessed in 15 regional citrate-anticoagulated dialysis sessions and 30 heparin-anticoagulated sessions. The median calcium loss was 0.8 mmol/h dialyzed in both groups (p = 0.43), and end of treatment ionized calcium was the same in both groups (1.07 ± 0.04 mmol/L).

LIMITATIONS

Our findings for calcium balance, efficacy, and safety are valid only for the protocol studied, which excluded patient with severe liver dysfunction.

CONCLUSIONS

Regional citrate dialysis can be performed safely and effectively using a sparse plasma calcium sampling protocol. The calcium balance induced by this protocol is not different to that seen in standard heparin-anticoagulated dialysis, but in the absence of prospective studies, it is unknown whether this is optimal for patient care.