[Hypercalcemic crisis. Exacerbation of an existing hypercalcemia syndrome]

Acute hypercalcemic crisis is the life-threatening exacerbation of an existing hypercalcemia syndrome, which is characterized by additional cerebral symptoms such as clouding of consciousness, somnolence and coma as well as rapid deterioration of renal function. Possible causes are diseases associated with severe hypercalcemia, such as malignant diseases, primary and tertiary hyperparathyroidism, vitamin D poisoning and treatment with calcium, vitamin D and calcium-containing ion exchangers in renal insufficiency. Nowadays the specific diagnosis can usually be established quickly and simply, since only in primary and tertiary hyperparathyroidism are calcium and the intact parathormone elevated. The aim of treatment is to bring about an effective reduction in serum calcium by inhibiting bone resorption and increasing calcium excretion in the urine. Today, the substances calcitonin, biphosphonate, mithramycin (plicamycin) and glucocorticoids, each with a different mode of action, are available. In patients with underlying malignant diseases these substances are used to supplement the treatment of the malignancy, while in hyperparathyroidism they are administered prior to operative parathyroidectomy.