Renal osteodystrophy and aluminum bone disease in CAPD patients

Renal failure is frequently associated with osteodystrophia due to secondary hyperparathyreoidism and/or increased aluminum intake. The problem of hypercalcemia and hyperphosphatemia can more easily controlled by CAPD than by hemodialysis. Total serum and ionized calcium levels are rapidly normalized by a CAPD regime of four 2-1 exchanges with 1.75 mmol/l Ca. Under the same CAPD regime 250-300 mg phosphate are removed per day. Depending on the ingestion of phosphate, 100-200 mg phosphate per day remain to be removed by phosphate binding agents. Since the main source of aluminum in CAPD patients is oral ingestion of aluminum-containing phosphate binders, serum levels should be regulated by diet and calcium carbonate. To suppress PTH secretion serum ionized calcium levels need to be maintained at the upper limit of normal. This can also be achieved by the use of oral calcium carbonate. Vitamin D or analogs should be prescribed only when clinically indicated by persistent hypocalcemia, osteitis fibrosa or non-aluminum related osteomalacia.