Hypercalcemia: Causes, Symptoms & Treatment

Total calcium level exceeding 10.5 mg/dL or an ionized calcium level exceeding 2.7mEq/L

CAUSES

1. Endocrine causes: Primary hyperparathyroidism, hyperthyroidism, pheochromocytoma, adrenal insufficiency, and acromegaly

2. Malignancies: Squamous cell carcinoma of the lung, breast cancer, kidney cancer, myeloma, and leukemia

3. Granulomatous disorders: Sarcoidosis, tuberculosis, histoplasmosis, and coccidioidomycosis

4. Medications: Excessive vitamin D or A intake, thiazides, lithium, and hormonal therapy for breast cancer can cause hypercalcemia.

5. Miscellaneous: Immobilization, Paget disease, dehydration, excess calcium ingestion, and milk-alkali syndrome

CLINICAL FEATURES

1. Signs and symptoms: Weakness, depression, confusion, lethargy, personality changes, nausea, vomiting, anorexia, constipation, headache, and abdominal pain

2. Physical examination findings: Dehydration, decreased motor strength, decreased mental status, ataxia, hyporeflexia, fractures, hypertension, weight loss, renal insufficiency, and cardiac arrest

EVALUATION

1. Laboratory studies should include ionized calcium levels; serum calcium, protein, phosphate, magnesium, BUN, creatinine, glucose, amylase, and lipase levels; a serum electrolyte panel; and a CBC.

2. Electrocardiography: ECG abnormalities include shortening of the QT interval, widening of T waves, bradyarrhythmias, bundle branch blocks, and second-degree and complete heart block.

THERAPY

Treatment is required for symptomatic patients with calcium levels greater than 12mg/dL who are unable to maintain a good fluid intake or have abnormal renal function.

1. Fluid replacement: Because patients with hypercalcemia are usually dehydrated, the initial and safest treatment is the restoration of volume with large amounts of saline (5 to 10 L of normal saline in the first 24 hours).

2. Pharmacologic therapy

a) Furosemide (1 to 3 mg/kg) can be administered intravenously to enhance urinary output and increase renal excretion of calcium.

b) Calcitonin (2 to 4 IU/kg intramuscularly every 12 hours) diminishes calcium levels, usually within 12 hours. Calcitonin is useful for the initial treatment of symptomatic hypercalcemia greater than 14 mg/dL.

c) Bisphosphonates are used for the longer-term management of hypercalcemia related to bone resorption.

3. Dialysis: Patients with severe symptoms and patients with cardiac or renal disease

DISPOSITION

Patients with a calcium level greater than 12 mg/dL, symptoms or abnormal renal function require admission for continuous cardiac monitoring and serial calcium levels.