Hypercalcaemia

Question 1

Explain calcium balance in the body

Answer 1

• Majority of the bodies calcium is stored in the bone (30000mmol). This is stored in bone formation and released into the ECF by bone reabsorption
• In the ECF there is approx 20mmol of Calcium
• Calcium is excreted really (approx 5mmol)
• Calcium passes though the GI tract, approx 25 mmol enters, 10 mmol is moved into the ECF, 5mmol is moved from the ECF to the GI tract and 20 mmol is excreted

Question 2

What is the effect of parathyroid hormone?

Answer 2

• Increases bone resorption
• Increases tubule Ca2+ reabsorption in the kidney
• Increases the conversion of 25-hydroxy vitamin D to 1,25-hydroxy vitamin D, which increases the intestinal absorption of calcium

Question 3

What are the clinical features of hypercalcaemia?

Answer 3

•Neurological:

• lethargy
• confusion
• irritability
• depression
• coma

•Gastrointestinal

• anorexia
• nausea
• constipation
• abdominal pain

• Renal

• thirst
• polyuria
• renal calcium position (leading to renal calculi or nephrocalcinosis)

•Cardiac
- arrhythmia

Question 4

Explain the management of hypercalcaemia depending on calcium level

Answer 4

• <3.0mmol/L - often asymptomatic
• 3.0-3.5mmol/L - may be symptomatic, prompt treatment is indicated
• > 3.5mmol/L requires urgent correction

Question 5

What is the next investigation when you discover a patient has hypercalcaemia?

Answer 5

Measure the PTH:
•If detectable/high then PTH dependent cause
•If undetectable PTH then independent cause

Question 6

What are the PTH dependent causes of hypercalcaemia?

Answer 6

• Primary hyperparathyroidism
• Tertiary hyperparathyrodisim
• Familial hypercalcaemic hypocalcinuria

Question 7

What are the PTH independent causes of hypercalcaemia?

Answer 7

• Malignancy
• Drugs: thiazides
• Endocrine: Addisons, thyrotoxicosis
• Bone: immobilisation
• Vitamin D excess
• Renal: rhabdomyolysis or renal failure

Question 8

What should you look for during examination of someone with hypercalcaemia?

Answer 8

• Cognition
• fluid status
• Full examination of underlying conditions

Question 9

What investigations should you do in a patient with hypercalacemia?

Answer 9

- Bloods:
•Bone profile 
•PTH 
•UEs
- ECG

Question 10

What should you do once you have diagnosed primary hyperparathyroidism?

Answer 10

Assess for end organ damage of the kidneys/bones
•Renal US or abdominal X ray
•DEXA scan

Question 11

What is the management of primary hyperparathyroidism?

Answer 11

• Outpatient
• Adequate hydration
• Conservative management or surgical management (parathyroidectomy)

Question 12

What should you measure to look for bone involvement?

Answer 12

Alk phosphatase

Question 13

What investigations should you carry out in OTH independent hypercalcaemia lily due to malignancy?

Answer 13

• Check PSA
• Myeloma screen
• blood film
• 1,25-OH vitamin D
• Cross sectional imaging ± LN biopsy