- Definition: serum calcium > 10.5 mg/dL
- Causes:
- Malignant disorders:
multiple myeloma, cancer metastatic to bone
- Endocrine disorders:
hyperparathyroidism, hyperthyroidism
- Granulomatous disorders:
sarcoidosis, tuberculosis
- Medication‑induced causes:
vitamins A and D, thiazide diuretics
- Other factors:
dehydration, rhabdomyolysis
Clinical features
- Neuro: lethargy, altered mental status, seizures, coma
- Cardiac: bradycardia, AV block, atrial fibrillation, VT
- GI: abdominal pain, constipation, nausea
- Musculoskeletal: bone pain
- Renal: polyuria, renal stones
- Neuropsychiatric: anxiety, depression, hallucinations
ECG changes
Treatment
| Therapy | Dose & Route | Notes |
|---|
| 0.9% normal saline | Volume repletion: 500–1000 mL/h IV for 2–4 h, then saline 200–300 mL/h | Target urine output ~2 L/day |
| Furosemide | 20–40 mg IV | Use after volume repletion for saline diuresis |
| Bisphosphonates (zoledronic acid) | 4 mg IV over 15 min | For malignancy-associated hypercalcemia; recommended if Ca ≥ 12 mg/dL |
| Corticosteroids | Prednisone 1–2 mg/kg PO or hydrocortisone 200–300 mg IV | Used for Addison’s disease or steroid-responsive malignancies |
| Calcitonin | 4 units/kg SC/IM | |
| Hemodialysis | | Consider for life-threatening arrhythmia or heart block |