Hypercalcaemia
Hypercalcaemia is a serum calcium>2.62 mmol/L (normal range 2.12–2.62 mmol/L). It may be an asymptomatic laboratory finding. Symptoms usually become apparent with levels>3.50 mmol/L.
Symptoms and Signs
These depend on the patient’s age, duration and rate of increase of plasma calcium and the presence of concurrent medical conditions. Symptoms and signs include nausea and vomiting, fatigue, depression, confusion, psychosis; abdominal pain, constipation, acute pancreatitis, peptic ulceration, polyuria/nocturia, haematuria, renal colic, renal failure, bone pain, hypertension and arrhythmias. Classical symptoms of hypercalcaemia in association with hyperparathyroidism include ‘stones, bones, abdominal groans and psychiatric overtones’.
Investigations
■ Fasting calcium and phosphate
Ca ↑ PO4 ↓.
■ U&Es
↑ creatinine ↑ urea. Renal failure.
■ PTH levels
↑ hyperparathyroidism.
■ Protein electrophoresis and Bence Jones protein
Multiple myeloma.
■ ECG
Short QT interval. Widened T waves.
■ Serum amylase
↑ in acute pancreatitis associated with hyperparathyroidism.
■ AXR
Stones. Nephrocalcinosis.
■ US
Renal stones. Carcinoma of the kidney (inappropriate PTH secretion). Parathyroid lesions.
■ Skull X-ray
Myeloma. Abnormal sella turcica in MEN associated pituitary tumour. Paget’s disease of bone.
■ Sestamibi scan
Hyperparathyroidism.
■ 24-hour urinary calcium excretion
↑ calcium excretion in hyperparathyroidism (calcium-restricted diets).
