BACKGROUND: Continuous dialysis could provide benefit by constant potassium and phosphate. This study investigates the suitability of potassium and phosphate sorbents for incorporation in an extracorporeal capacity and regenerability testing. METHODS: Capacity testing was uraemic plasma. Regenerability was tested for potassium sorbents, with based on cationic exchange for sodium, with 0.1 M and 1.0 M NaCl. To phosphate sorbents, with adsorption based on anionic exchange, 0.1 M and NaHCO3 and NaOH were used. Subsequently, sodium polystyrene sulphonate (RES-A) and iron oxide hydroxide (FeOOH) beads were cartridge for testing in bovine blood using a recirculating blood dialysis circuit separated by a high-flux dialyzer (dynamic setup). was tested to assess whether this could limit calcium and magnesium RESULTS: In the batch-binding assays, zirconium phosphate most potently potassium (0.44 +/- 0.05 mmol/g) and RES-A was the best regenerable sorbent (92.9 +/- 5.7% with 0.1 M NaCl). Zirconium oxide hydroxide (ZIR- most potently adsorbed phosphate (0.23 +/- 0.05 mmol/g) and the sevelamer carbonate was the best regenerable sorbent (85.7 +/- 5.2% with NaHCO3). In the dynamic setup, a potassium adsorption of 10.72 +/- 2.06 h was achieved using 111 g of RES-A and a phosphate adsorption of 4.73 mmol in 3 h using 55 g of FeOOH. Calcium and magnesium preloading was reduce the net adsorption in 3 h from 3.57 +/- 0.91 to -0.29 +/- 1.85 +/- 0.05 to -0.31 +/- 0.18 mmol, respectively. CONCLUSION: RES-A and suitable, regenerizable sorbents for potassium and phosphate removal in regeneration. Use of zirconium carbonate and ZIR-hydr may further phosphate adsorption, but may compromise sorbent regenerability. Use of amines for phosphate adsorption may enhance sorbent regenerability. magnesium preloading considerably reduced net adsorption of these ions.
Wester, M., Simonis, F., Gerritsen, K. G., Boer, W. H., Wodzig, K. W. H., Kooman, J. P., & Joles, J. A. (2013). A regenerable potassium and phosphate sorbent system to enhance dialysis efficacy and device portability: an in vitro study. Nephrology Dialysis Transplantation, 28(9), 2364-2371. https://doi.org/10.1093/ndt/gft205