Hypercalcémies sévères

Severe hypercalcemia is an infrequent medical condition that induces, however, life-threatening cardiac, neurological and renal consequences. Severe hypercalcemia is defined as a serum calcium concentration higher than 3.5 mmol l-1 or higher than 3 mmol l-1 associated with symptoms. Calcium serves many important biologic, structural, electrical and information roles both outside and inside the cell. Regulation of calcium concentrations within physiologic compartments is therefore critically important for normal cellular function. Normal calcium homeostasis is regulated by 3 calciotropic hormones, parathyroid hormone (PTH), vitamin D and calcitonin. The most common causes of hypercalcemia are primary and secondary hyperparathyroidism and malignancy-associated hypercalcemia. The etiological diagnosis is established on the basis of the clinical pattern and on the measurement of PTH as well as PTH related peptide, which is produced by neoplasic cells. The management of severe hypercalcemia requires ICU admission, general measures as hydration and loop diuretic agents, and specific therapy by biphosphonates with or without calcitonin.