E83.5 + (E21.0/D71)
DESCRIPTION
When serum calcium (corrected for albumin) concentrations exceed the upper limit of normal.
Aetiology
- Ambulatory patients: most common cause is hyperparathyroidism (>90% of cases).
- Hospitalised patients: malignancies are the most common cause (65% of cases). Hyperparathyroidism accounts for another 25%.
- Granulomatous disease (e.g. sarcoid).
- Immobilisation in those with high bone turnover.
Investigations
Draw blood for parathyroid hormone (PTH) and simultaneous calcium, phosphate, magnesium, albumin, creatinine and sodium and potassium, and 25 hydroxy-vitamin D concentrations.
A detectable PTH in the presence of hypercalcaemia indicates PTH-dependent hyperparathyroidism.
MEDICINE TREATMENT
Hypercalcaemia
Patients with moderate/severe hypercalcaemia should be kept well hydrated and may need several litres of fluid.
Avoid thiazide diuretics in the acute setting as they increase serum calcium concentration.
The addition of furosemide has not been shown to be of benefit.
For symptomatic hypercalcaemia:
- Sodium chloride solution 0.9%, IV infusion, 4–6 L in 24 hours.
- Monitor urine output.
If still symptomatic after 24 hours and adequate hydration, or if initial serum calcium is >3 mmol/L:
ADD
- Bisphosphonates, e.g.:
- Zoledronic acid, IV infusion, 4 mg over 15 minutes (specialist initiated).
- eGFR 35 to 60 mL/minute, adjust dose in consultation with specialist.
- Note: Do not use if eGFR <35 mL/minute.
In patients with granulomatous disease and haematological malignancies:
- Corticosteroids (intermediate-acting) e.g.:
- Prednisone, oral, 40 mg depending on response, daily.
REFERRAL
When a diagnosis of hyperparathyroidism is confirmed or other cause is not obvious.