Correction of hypophosphatemia in patients on hemodialysis using a calcium-free dialysate with added phosphate

Three patients on long term hemodialysis were found to be hypophosphatemic. They were treated using a calcium-free dialysate to which phosphate was added to give a final concentration of 1 or 2 mmol/l. All corrected their low phosphates. Hypocalcemia developed in two patients when the calcium infusion rate was 15 ml/hour of 10% CaCl2. It is recommended that this should be increased to 20 ml/hour. Under these circumstances, correction of hypophosphatemia is possible with the transfer of approximately 30-35 mmol phosphate over a four-hour dialysis.