Peritoneal dialysis in the treatment of severe hypercalcemia.

A 56-year-old man with multiple myeloma and compromised renal function underwent peritoneal dialysis for the treatment of severe hypercalcemia. During dialysis, peritoneal clearances of total calcium, unbound calcium, urea, and creatinine were assessed. Clearances of total calcium (4.8 +/- 0.4 ml/min) and unbound calcium (7.8 +/- 0.5 ml/min) were shown to vary directly with the clearances of urea (15.5 +/- 1.3 ml/min) and creatinine (8.5 +/- 0.8 ml/min). Despite relatively low clearances of all these solutes, during the period of 42 hours, 1,638 mg of calcium was removed in the dialysate and total serum calcium decreased from 17.6 mg/dl to 10.2 mg/dl. Our data indicates that peritoneal dialysis is an effective adjunct in controlling severe hypercalcemia and should be considered when other forms of therapy are inadequate.