Hypercalcaemia

High-Yield Tips

  • 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).

Definition

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.

Classification

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

Severity

  • Mild: 2.6 ≤ corr. calcium < 3.0 mmol/L
  • Moderate: 3.0 ≤ corr. calcium < 3.5 mmol/L
  • Severe: corr. calcium ≥ 3.5

Aetiology

💡
80-90% of cases result from 1° hyperparathyroidism or malignancy.

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

Clinical Presentation

History

  • 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
  • Other:
    • Weakness, malaise, apathy
    • Hyporeflexia
    • ↓ memory
    • Nephrogenic diabetes insipidus → polyuria and polydipsia
    • Arrhythmias → dyspnoea, palpitations, chest pain, presyncope/lightheadedness, syncope

Management

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By the time you know it’s hypercalcaemia, you likely have already done a primary survey.
  1. IV fluids (sodium chloride 0.9% 4-6 L over 24h)
  2. ECG. Changes may include:
    • QT shortening
    • Prolonged PR interval
    • Widened QRS interval
    • Notched QRS with increased voltage
    • AV block → cardiac arrest
  3. 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
  4. In acute life-threatening hypercalcaemia consider addition of parenteral calcitonin salmon 100 IU SC/IM/IV every 8-12h.
  5. Glucocorticoids may be required in refractory hypercalcaemia caused by malignancy, Vit D toxicity or sarcoidosis.
💡
If patient has renal failure, they may require dialysis → seek specialist advice.

Resources

  1. Therapeutic Guidelines
  2. LITFL: Hypercalcaemia
  3. LITFL: Hypercalcaemia DDx