When can a result of hypercalcaemia be trusted to be a true pathological finding?
When the specimen was tkaen without a venous cuff, and the result has been corrected for albumin concentration
What is considered to be severe hypercalcaemia?
Calcium >3.5mmol/L
How is severe hypercalcaemia managed?
- Saline infusion and furosemide, to maintain fluid balance and prevent fluid overload
- Correct hypokalaemia and hypomagnesaemia
- If calcium remains high, pamidronate disodium over 2-3 days
What are the main differential diagnoses for hypercalcaemia?
- Thiazide diuretics
- Bone metastases
- Thyrotoxicosis
- Primary or tertiary hyperparathyroidism
- Myeloma
- Sarcoidosis
- Vitamin D excess
- Ectopic parathyroid hormone
What suggests that thiazide diuretics are the cause of hypercalcaemia?
- Mild hypercalcaemia
- Drug history
- Normal phosphate and alkaline phosphatase
What confirms that thiazide diuretics are the cause of hypercalcaemia?
Normal calcium when drug stopped
Where are the common sources of bone metastases?
- Breast
- Bronchus
- Kidney
- Thyroid
- Ovary
- Colon
What suggests that bone metastases are the cause of hypercalcaemia?
- Normal phosphate
- Increased alkaline phosphatase
What confirms that bone metastases are the cause of hypercalcaemia?
Secondaries on bone scan
How is hypercalcaemia caused by bone metastases managed?
- Pamidronate over 2-3 days to lower calcium
- Approrpriate treatment of neoplastic process
What suggests that thyrotoxicosis is the cause of hypercalcaemia?
- Weight loss with good appetite
- Tremor
- Palpitations
- Agitation
- Goitre
- Mildly increased calcium
How is it confirmed that thyrotoxicosis is the cause of hypercalcaemia?
- Increased T3 or T4
- Greatly decreased TSH
- Normal phosphate and alkaline phosphatase
How is thyrotoxicosis managed?
- Propanolol o control symptoms
- Carbimazole
- Written warning about agranulocytosis
What suggests that hypercalcaemia is caused by primary or tertiary hyperparathyroidism?
- Fatigue
- Constipation
- Depression
- Impaired memory
- Renal colic and kidney stones
- Stomach ulcer
- Increased BP
- Pancreatitis
- Low phosphate and increased alkaline phosphatase
What confirms that hypercalcaemia is caused by hyperparathyroidism?
Increased plasma parathyroid levels
What suggests that hypercalcaemia is caused by myeloma?
- Low back pain
- Polyuria and polydipsia
- Spinal fracture
- Normal serum phosphate and alkaline phosphatase
What confirms that myeloma is the cause of hypercalcaemia?
- Paraprotein with immunoparesis on electrophoresis
- Hypercalcaemia
- Decreased Hb
- Bence-Jones protein in urine
- Spinal x-ray showing fracture with osteolytic lesion
How is myeloma treated?
- Correct very high calcium, and oral bisphosphonate to keep calcium down
- Analgesics for bone pain
- Local radiotherapy in progressive disease
- Prompt treatment of infections
- Transfusions for anaemia
- Chemotherapy using melphalan or cyclophosphamide in conjunction with steroids
What suggests that hypercalcaemia is caused by sarcoidosis?
- Cough
- Weight loss
- Night sweats
- Shortness of breath
- Erythema nodusum
- Increased phosphate and alkaline phosphatase
- Bilateral hilar shadows on CXR
What confirms that sarcoidosis is the cause of hypercalcaemia?
- Lung function tests
- Kveim test
- Biopsy from granuloma
- Increased vitamin D levels
- Increased ACE levels
How is hypercalcacemia in sarcoidosis managed?
- Correct very high calcium, and long-term prednisolone to control calcium
- In severe cases, methylprednisolone IV or immunosuppression
What suggests that vitamin D excess is the cause of hypercalcaemia?
- Drug history
- Increased phosphate
What confirms that vitamin D excess is the cause of hypercalcaemia?
Normal calcium when drug stopped
What is usually the cause of ectopic parathyroid hormone?
Lung cancer
