Hypercalcemia of acute renal failure. Clinical significance and pathogenesis.

Hypocalcemia is a frequent accompaniment of acute renal failure, but paradoxically hypercalcemia also has been described in association with acute renal failure. In this paper we describe two patients who provide some insights into both the potential clinical importance and mechanism of the hypercalcemia associated with acute renal failure. The clinical significance is emphasized by the presence of diffuse metastatic calcification observed at postmortem examination in one patient. In both patients the increase in serum calcium concentration was not coincident with a decrease in serum phosphorus concentration; when measured in one patient, serum levels of parathyroid hormone were undetectable. These findings, along with the consistent association with rhabdomyolosis, support the proposal that the hypercalcemia of acute renal failure is caused by dissolution of dystrophic calcifications in traumatized muscle and may lead to severe metastatic calcifications.