Severe immobilization hypercalcemia, renal insufficiency, and calcification.

Severe hypercalcemia with decreased renal function, hypertension, and renal calcifications developed in a 14-year-old boy who required prolonged immobilization for multiple fractures. Parathyroid hormone was not detectable in the serum. Urinary calcium excretion was high. Initially, mobilization was impossible and the patient was treated with a high fluid intake, low calcium intake, acidification of the urine, furosemide, and a passive exercise program. Renal function improved and renal calcifications resolved but hypercalcemia did not resolve. After mobilization the serum calcium concentration became normal rapidly. This treatment regimen is suggested for use in patients with immobilization hypercalcemia when mobilization is impossible.