CALCIUM-CONCENTRATION IN THE CAPD DIALYSATE - WHAT IS OPTIMAL AND IS THERE A NEED TO INDIVIDUALIZE

Objective: To evaluate risk/benefit of various continuous ambulatory p eritoneal dialysis (CAPD) dialysate calcium concentrations. Data Sourc es: A review of the literature on the effects of various CAPD dialysat e Ca concentrations on plasma Ca, plasma phosphate, plasma parathyroid hormone (PTH), doses of calcium carbonate, doses of vitamin D analogs , and requirements of aluminum-containing phosphate binders. Study Sel ection: Eleven studies of nonselected CAPD patients, and 13 studies of CAPD patients with hypercalcemia were reviewed. Results: In nonselect ed CAPD patients, treatment with a reduced dialysate Ca concentration (1.00, 1.25, or 1.35 mmol/L) improved the tolerance to calcium carbona te and/or vitamin D metabolites and reduced the need for Al-containing phosphate binders. When using dialysate Ca 1.25 or 1.35 mmol/L, the i nitial decrease of plasma Ca and increase of PTH could easily be rever sed with an immediate adjustment of the treatment. After 3 months, sta ble plasma Ca and PTH levels could be maintained using only monthly in vestigations. In patients with hypercalcemia and elevated PTH levels, treatment with dialysate Ca concentrations below 1.25 mmol/L implied a considerable risk for the progression of secondary hyperparathyroidis m. When hypercalcemia was present in combination with suppressed PTH l evels, a controlled increase of PTH could be obtained with a temporary discontinuation of vitamin D and/or a reduction of calcium carbonate treatment in combination with a dialysate Ca concentration of 1.25 or 1.35 mmol/L. Conclusion: Most CAPD patients can be treated effectively and safely with a reduced dialysate Ca concentration of 1.35 or 1.25 mmol/L. Treatment with dialysate Ca concentrations below 1.25 mmol/L s hould not be used. A small fraction of patients with persistent hypoca lcemia need treatment with high dialysate Ca, such as 1.75 mmol/L.