Recognize
- Mild 10.5–12 · Moderate 12–14 · Severe / crisis > 14 mg/dL
- "Stones, bones, groans, psychiatric overtones" — nephrolithiasis, bone pain, abd pain, AMS, polyuria, dehydration
- EKG: short QT, bradyarrhythmias
- Causes: malignancy (PTHrP, lytic mets, myeloma), primary hyperparathyroid, vit D toxicity, milk-alkali, thiazides, immobilization, granulomatous disease
Volume resuscitation
- Normal saline 200–300 mL/h — restore euvolemia, target UOP 100–150 mL/h
- Avoid loop diuretics unless volume overload (fluid first; furosemide only after rehydration)
Calcitonin (rapid)
- Calcitonin 4 IU/kg IM/SC q12h (max 8 IU/kg q6h)
- Onset 4–6 h · ↓ Ca by 1–2 mg/dL · tachyphylaxis after 48 h
- Bridge until bisphosphonates active
Bisphosphonates / denosumab
- Zoledronic acid 4 mg IV over 15 min (preferred for malignancy)
- Pamidronate 60–90 mg IV over 2–4 h
- Onset 24–48 h · duration weeks
- Avoid bisphos if GFR < 30 — use denosumab 60–120 mg SC
Refractory / crisis
- Hemodialysis: severe (> 18), refractory, AKI, CHF preventing fluids
- Glucocorticoids (prednisone 20–40 mg) for vit D / granulomatous / lymphoma
- Stop offending agents (Ca, vit D, thiazide, lithium)
Disposition
- Admit: Ca > 14, symptomatic, AKI, AMS, EKG changes