Case:
In morning report we discussed a perplexing case of a patient who presented with new onset hypercalcemia. Let’s Review an approach to hypercalcemia.
Overview:
- Symptoms
- Differential Diagnosis
- Investigations
- Treatment
Symptoms:
“Groans, Stones, Bones, Psychiatric Overtones, Thrones”
- abdominal pain, nausea, vomiting, pancreatitis
- kidney stones
- bony pain, fractures
- confusion, delirium, coma
- constipation/polyuria
Differential Diagnosis:
Investigations:
- CBC, lytes (can get contraction alkalosis à so high bicarb), creatinine
- PTH, 25-OH-Vit D
- Depending on above and clinical picture consider:
- 24 hour urine calcium
- Malignancy work up as needed: CXR/CT, SPEP/UPEP, imaging etc
- ECG (short QT)
- 1,25-VitD, PTHrP, TSH, Vitamin A level
Treatment:
- Goals: lower calcium, treat underlying cause
- Fluids, fluids, fluids for everyone: increases urinary calcium excretion. Onset in hours. Typically NS (normal saline) 150-200cc/hr to target a urine output of 100cc/hr. Monitor for volume overload.
- Furosemide is not a maintstay of treatment. Give only if patient is now fluid overloaded from all the fluids you gave
- Specific treatments that you tailor to your patient:
- Bisphosphonates: Inhibit bone resorption via interference with osteoclast recruitment and function. Most benefit is in patients with malignancy as their underlying cause
- Zoledronic Acid: 4 mg IV (preferred) (vs Pamidronate: 60-90 mg IV or lower if renal impairment). Works in 2-3 days.
- Bisphosphonates: Inhibit bone resorption via interference with osteoclast recruitment and function. Most benefit is in patients with malignancy as their underlying cause
- If hypercalcemia is severe, can consider calcitonin: Also interferes with osteoclast function and inhibits bone resorption but also promotes urinary calcium excretion. Onset in 4-6 hours but you get tachyphylaxis at ~48h.
- 4 IU/kg Subcut or IM. Repeat serum calcium in a few hours. Calcitonin can be repeated and increased to 4-8 IU/kg sc q6-12h.
- Denosumab: RANK-L inhibitor. Used typically in patients with severe, symptomatic hypercalcemia of malignancy not responsive to bisphosphonates or in whom bisphophonate use is contraindicated due to renal failure (GFR is not a limiting factor for its use like bisphosphonates).
- Steroids: usually only for granulomatous disaese or lymphoma.
- Decreases intestinal calcium absorption and decreases 1, 25-OH-VitD. HOWEVER, not to be started overnight, as biopsy may need to be done before initiation of steroids.
- Hemodialysis: if the patient is anuric.