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Kidney Week

Abstract: FR-PO746

Calcium Mass Balance During Hemodialysis: A Comparison of Different Dialysate Calcium Concentrations Including Citrate-Acid Calcified Dialysate

Session Information

Category: Dialysis

  • 701 Dialysis: Hemodialysis and Frequent Dialysis


  • ter Meulen, Karlien J., Maastricht University Medical Centre, Maastricht, Netherlands
  • van der Sande, Frank, Maastricht University Medical Centre, Maastricht, Netherlands
  • Konings, Constantijn, Catharina Hospital, Eindhoven, Netherlands
  • Dekker, Marijke J.E., Maastricht University Medical Centre, Maastricht, Netherlands
  • Canaud, Bernard J., FMC Deutschland GmbH, Bad Homburg, Germany
  • Kooman, Jeroen, Maastricht University Medical Centre, Maastricht, Netherlands

Bone and mineral disorders are still cause of morbidity and mortality among chronic kidney diseases, even though adjustments made in therapy and techniques. The optimal dialysate calcium (dCa) and magnesium (dMg) is debated in hemodialysis as international guidelines differ. Citric-acid dialysate may affect Mg and Ca removal during dialysis. The aim of this study was to compare the mass balances in calcium (CaMB) and magnesium (MgMB) between bicarbonate/acetic-acid dialysate with dCa1.50 (dAcetCa1.50) and dCa1.25 (dAcetCa1.25), as well with citric-acid dialysate with dCa1.50 (dCitCa1.50) and dMg of 0.5 mmol/l.


Twenty patients were enrolled in this 4-week prospective multicenter randomized cross-over trial where they received a baseline week (dAcetCa1.50), followed by the randomized sequence of dAcetCa1.25 or dCitCa1.50 for one week and the alternate treatment was provided after a washout week with dAcetCa1.50. Spent dialysate was collected from the outlet of the dialysis machine in a fractionated way.


Eighteen patients completed the study, one session was excluded due to unclear dialysate. CaMB was in general positive during dAcetCa1.50 and negative during dAcetCa1.50 and dCitCa1.50. MgMB was negative during all different treatments There was an inverse correlation for pre-dialytic serum ionized calcium (iCa) with CaMB in dAcetCa1.50 (r; p-value) (-0.687; 0.002) and in dCitCa1.50 (-0.725; 0.001). This was also found for total calcium in dAcetCa1.50 (-0.579; 0.012) and dCitCa1.50 (-0.708; 0.001), and corrected total calcium in dAcetCa1.50 (-0.687; 0.002) and dCitCa1.50 (-0.725; 0.001).


Our study shows that whereas dAcetCa1.50 leads to net gain of calcium by the body during dialysis, net loss occurs during dCitCa1.50, with levels comparable to dAcetCa1.25. Given the strong dependence of CaMB on pre-dialytic iCa, the introduction of dCa solution with 1.375 mmol/l may be relevant for individualizing CaMB during dialysis. Major losses of Mg occur during the use of conventional dialysis solutions.

Total mass balances per dialysate
 NdAcetCa1.50 (A)NdAcetCa1.25 (B)NdCitCa1.50 (C)Np-valuePost-hoc
185.67 [0.59; 9.54]17-2.4 [-6.19; 1.78]17-2.00 [-5.26; -0.18]16<0.001<0.001<0.0010.906
18-5.06 [-6.04; -3.12]17-4.00 [-6.17; -3.29]17-4.40 [-6.00; -3.49]170.204   

Data are presented as median [25th; 75th percentile].


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