- Corrected calcium > 3.0 mmol/L is concerning.
- Majority of cases result from 1° hyperparathyroidism or malignancy.
- Stones, bones, groans, psychic moans.
- Initial management is to facilitate renal excretion of calcium by significant IV fluid administration (4-6 L of 0.9% sodium chloride over 24h).
Serum total calcium concentration, corrected for albumin aka corrected calcium > 2.60 mmol/L.
Note: if the albumin concentration is significantly abnormal, serum ionised calcium should be measured directly.
Parathyroid-dependent hypercalcaemia (PTH-D) vs parathyroid-independent hypercalcaemia (PTH-IH)
Determined by simultaneously measuring serum calcium and parathyroid hormone concentrations
- PTH-DH = PTH ≥ upper end of normal
- PTH-IH = normal or ↓ PTH
- Mild: 2.6 ≤ corr. calcium < 3.0 mmol/L
- Moderate: 3.0 ≤ corr. calcium < 3.5 mmol/L
- Severe: corr. calcium ≥ 3.5
Poor Harry Thinks Very Slowly
- Primary hyperparathyroidism or Primary adrenal insufficiency
- Hypercalcaemia of malignancy
- Thiazide diuretics
- Vitamin D toxicity
- Sarcoidosis (or other granulomatous disorders) or Severe hyperthyroidism
- Stones, bones, groans, psychic moans”
- Stones → renal calculi
- Bones → bone pain from osteolysis and fractures
- Abdominal groans → abdominal pain, nausea and vomiting, constipation, pancreatitis
- Psychic moans → depression, delirium
- Weakness, malaise, apathy
- ↓ memory
- Nephrogenic diabetes insipidus → polyuria and polydipsia
- Arrhythmias → dyspnoea, palpitations, chest pain, presyncope/lightheadedness, syncope
- IV fluids (sodium chloride 0.9% 4-6 L over 24h)
- ECG. Changes may include:
- QT shortening
- Prolonged PR interval
- Widened QRS interval
- Notched QRS with increased voltage
- AV block → cardiac arrest
- If not responding to rehydration, consider bisphosphonate IV infusion (zoledronic acid 4mg IV over > 15m)
- Note: patients must be well hydrated before receiving bisphosphonate therapy
- Note: the bisphosphonate infusion can cause transient influenza-like symptoms → paracetamol use
- In acute life-threatening hypercalcaemia consider addition of parenteral calcitonin salmon 100 IU SC/IM/IV every 8-12h.
- Glucocorticoids may be required in refractory hypercalcaemia caused by malignancy, Vit D toxicity or sarcoidosis.