Hypercalcaemia

Question 1

Define hypercalcaemia

Answer 1

Total correct serum Ca 2+ level above 2.6mmol/L OR ionised Ca2+ level > 1.35 mmol/L

Question 2

90% of cases of hypercalcaemia will be due to ___ or _____. All other causes are rare.

Answer 2

Malignancy or,
Primary hyperparathyroidism (adenoma of the parathyroid glands)

Question 3

What is the normal total serum calcium concentration?

Answer 3

2.1-2.6 mmol/L

Question 4

How does malignancy cause hypercalcaemia?

Answer 4

Mechanisms by haematological, humoral (PTHrP) or direct skeletal metastases

Question 5

Which organs are involved in malignancy-associated hypercalcaemia?

Answer 5

Paired organs * lungs (squamous cell carcinoma), kidneys, ovaries, breast, adrenal glands
Plus MM and lymphomas

Question 6

How does PTHrP cause hypercalcaemia?

Answer 6

The malignant cells release PTH related protein which mimics PTH action by preventing renal excretion and activating osteoclast induced bone resorption

Question 7

How does multiple myeloma cause hypercalcaemia?

Answer 7

Cytokine mediated

Question 8

How does lymphoma cause hypercalcaemia?

Answer 8

Lymphomas produce calcitriol (i.e. vitamin D)

Question 9

How do bony mets cause hypercalcaemia?

Answer 9

Direct osteolytic effect on the bone

Question 10

What are the main symptoms of hypercalcaemia?

Answer 10

Bones, stones, groans, thrones and psychic moans
• Bones: Increased osteolysis and fractures
• Stones: renal colic, hypercalcaemic stones
• Groans (abdo): anorexia, N/V, constipation, PUD, pancreatitis
• Pyschic moans: depression, confusion, hallucinations, coma
• Thrones: sitting - polyuria and constipation

Question 11

How do we manage hypercalcaemia?

Answer 11

First: IV saline for hydration and flushing of Ca
Second: bisphosphonates to inhibit bone breakdown and promotion of renal excretion of Ca