Hypercalcemia Management

Diagnostic Evaluation

The initial diagnostic workup for hypercalcemia should include laboratory evaluation of serum calcium, albumin, intact parathyroid hormone (iPTH), parathyroid hormone-related protein (PTHrP), 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, serum phosphorus, magnesium, blood urea nitrogen, and creatinine to determine the underlying cause 1, 2
Calculate corrected calcium using the formula: Corrected calcium (mg/dL) = Total calcium (mg/dL) - 0.8 × [Albumin (g/dL) - 4] to accurately assess severity 2
Classify severity of hypercalcemia as mild (>5.0 to <5.5 mEq/L or >10 to <11 mg/dL), moderate (5.5 to 6.0 mEq/L or 11 to 12 mg/dL), or severe (>6.0 mEq/L or >14.0 mg/dL) 2
Evaluate for symptoms based on severity, including polyuria, polydipsia, nausea, confusion, vomiting, abdominal pain in mild/moderate cases, and mental status changes, bradycardia, hypotension, dehydration, acute renal failure in severe cases 2, 3

Administer IV normal saline to correct hypovolemia and promote calciuresis as the first intervention, with a goal of maintaining urine output of at least 100 ml/hour (3 ml/kg/hour in children <10 kg) 1
For moderate to severe hypercalcemia, especially malignancy-associated, administer bisphosphonates after initiating hydration, with zoledronic acid preferred over pamidronate for initial treatment 1, 2, 3
Calcitonin can be used for immediate short-term management of severe symptomatic hypercalcemia while waiting for bisphosphonates to take effect 1
Glucocorticoids are effective for vitamin D-mediated hypercalcemia (sarcoidosis, lymphomas, vitamin D intoxication) 1, 3
Denosumab (120 mg subcutaneously) may be used for patients with refractory hypercalcemia, especially those with renal impairment 2

Avoid vitamin D supplements in patients with hypercalcemia, particularly in early childhood 1, 3
Monitor serum calcium, renal function, and electrolytes regularly to assess treatment effectiveness 1, 3
For pediatric patients with hypercalcemia (e.g., Williams syndrome), a low-calcium diet and increased water intake under medical supervision are recommended 3, 4
Watch for complications of treatment, including renal toxicity and osteonecrosis of jaw with bisphosphonates, and hypocalcemia post-treatment with denosumab 2

Avoid NSAIDs and intravenous contrast media in patients with renal impairment to prevent worsening renal function 1
Do not restrict calcium intake without medical supervision in patients with normocalcemia 1
Hyperalbuminemia can mask true calcium status; always calculate corrected calcium or measure ionized calcium 2
Remember that treatment of the underlying cause (e.g., parathyroidectomy for primary hyperparathyroidism, cancer therapy for malignancy-associated hypercalcemia) is essential for long-term management 3