Synopsis
Confirm and classify hypercalcaemia, recognise organ-threatening severity, restore volume safely and direct definitive care through the PTH response.
- Verify an unexpected total calcium using albumin adjustment or ionised calcium when protein or acid-base disturbance makes total calcium unreliable.
- The first mechanistic branch is PTH: hypercalcaemia should suppress it, so a high or inappropriately normal PTH indicates PTH-dependent disease.
- Primary hyperparathyroidism and malignancy cause most clinically important hypercalcaemia, but medicines, granulomatous disease, thyrotoxicosis, immobility and vitamin excess matter.
Investigation priorities
Confirm true hypercalcaemia and establish severity when albumin or critical illness affects total calcium.
Management branches
Marked calcium elevation accompanies symptoms, dehydration, renal injury or ECG concern.
- Assess ABCDE, ECG, fluid balance and cardiac-renal comorbidity, repeat calcium and obtain PTH and renal bloods without postponing treatment.
- Give monitored intravenous 0.9% sodium chloride to restore euvolaemia, adjusting rate to response and seeking renal or critical-care help when fluid tolerance is limited.
Confirmed hypercalcaemia is stable enough for mechanistic investigation.
Key medicines
Intravenous 0.9% sodium chlorideUse the Society for Endocrinology and local resuscitation regimen, titrating the initial and ongoing rate to blood pressure, urine output, sodium, renal function and cardiac reserve rather than prescribing a fixed volume for every adult.
Intravenous bisphosphonateAfter adequate rehydration, select the antiresorptive for the cause and renal function. For adult tumour-induced hypercalcaemia with albumin-corrected calcium at least 3.0 mmol/L, the current zoledronic acid SmPC recommends a single 4 mg intravenous infusion over no less than 15 minutes; use the specific BNF, SmPC or specialist protocol for other causes or products.