Hypercalcaemia

Question 1

What is hypercalcaemia?

Answer 1

High calcium levels in the blood serum

Question 2

What are the causes of excessive PTH secretion leading to hypercalcaemia?

Answer 2

(1) Primary hyperparathyroidism (adenoma or hyperplasia)

(2) Tertiary hyperparathyroidism

Question 3

How does malignancy cause hypercalcaemia?

Answer 3

(1) bone metastases
(2) PTH-related protein secretion
(3) Osteoclast-activating factors from tumours

Question 4

What are the classic symptoms of hypercalcaemia?

Answer 4

“Stones, Bones, Groans, and Psychic Moans”

Stones → Gallstones, renal stones

Bones → Bone pain, fractures, osteoporosis

Groans → Abdominal pain, pancreatitis, peptic ulcers

Psychic Moans → Depression, confusion, psychiatric symptoms

Question 5

What are the acute symptoms of hypercalcaemia?

Answer 5

Thirst, dehydration, confusion, polyuria

Question 6

What are the chronic symptoms of hypercalcaemia?

Answer 6

(1) Myopathy
(2) Fractures
(3) Osteopenia
(4) Depression
(5) Hypertension
(6) Pancreatitis
(7) Duodenal ulcers
(8) Renal calculi

Question 7

What ECG finding is associated with hypercalcaemia?

Answer 7

Shortened QT interval
J wave

Question 7

What blood test abnormalities indicate primary hyperparathyroidism?

Answer 7

1. Raised calcium
2. Low phosphate
3. Detectable or elevated PTH

Question 8

What blood test abnormalities suggest malignancy-related hypercalcaemia?

Answer 8

1. Raised calcium
2. Undetectable PTH
3. Raised alkaline phosphatase (ALP)

Question 9

What are the key biochemical findings in familial hypocalciuric hypercalcaemia (FHH)?

Answer 9

1. Mild hypercalcaemia
2. Low urine calcium excretion
3. Normal/high PTH
4. Normal ALP
5. High phosphate

Question 10

How is acute severe hypercalcaemia managed?

Answer 10

1. IV 0.9% saline (4-6L in 24 hours) for rehydration
2. Consider loop diuretics
   (after rehydration) to prevent calcium reabsorption
3. Bisphosphonates to inhibit bone resorption (effect in 2-3 days, max at 1 week)
4. Steroids
   (eg, prednisolone 40-60 mg/day)
   in cases like sarcoidosis

Question 11

When is surgery indicated for primary hyperparathyroidism?

Answer 11

(1) Calcium >2.85 mmol/L
(2) Age <50
(3) Reduced eGFR (<60 mL/min)
(4) End-organ damage

Question 12

What is cinacalcet, and when is it used?

Answer 12

A calcium mimetic that reduces PTH secretion, used when surgery is not an option or in tertiary hyperparathyroidism/parathyroid carcinoma

Question 13

How is malignancy-related hypercalcaemia managed?

Answer 13

Treat the underlying malignancy

Question 14

Which type of lung cancer can cause hypercalcaemia through PTHrP release?

Answer 14

Squamous cell

Question 15

What are the key adverse signs of severe hypercalcaemia?

Answer 15

1. Cardiac arrhythmia
2. Seizures/coma
3. Dehydration
   (acute kidney injury will often occur)

Question 16

What are the key treatments in hypercalcaemia?

Answer 16

(1) IV fluid rehydration (0.9% saline)
(2) IV bisphosphonate as second line

(3) Consideration of furosemide/prednisolone/calcitonin as third-line treatments

Question 17

What is the first line management of acute hypercalcaemia?

Answer 17

Aggressive IV fluids

Question 18

What is the best test to assess bone related damage in the context of hypercalcaemia?

Answer 18

DEXA bone scan

Question 19

Which drugs can cause hypercalcaemia?

Answer 19

Vitamin D
Vitamin A
Lithium
Thiazides

Question 20

What level of hypercalcaemia requires urgent treatment regardless of symptoms?

Answer 20

Greater than 3.5 mmol/L

Question 21

What does undetected PTH mean?

Answer 21

Undetected PTH (parathyroid hormone) means that the hormone level is so low that it is below the test’s detection limit

Question 22

Possible causes of undetected PTH include what?

Answer 22

(1) Hypoparathyroidism
(underactive parathyroid glands)

(2) Autoimmune conditions

(3) Surgical removal of the parathyroid glands

(4) Very high calcium levels

Question 23

A 46-year-old man arrives at the acute medical unit feeling generally unwell. On routine bloods you find his Calcium levels are 1.8 (normal 2.25-2.5)
Which clinical features might you expect to observe?

Answer 23

1. Chvostek sign (to do with nerves)
2. Perioral and extremity numbness
3. Laryngospasm Arrhythmia

Question 24

A 67-year-old man presents to his GP with symptoms of increasing fatigue, bone pain, and constipation. He has a history of squamous cell lung cancer diagnosed three months ago and is currently under the care of the hospital oncology team. The GP orders blood tests to investigate the cause of his recent symptoms. What blood test result is most likely to be elevated in this scenario?

Answer 24

Parathyroid hormone-related peptide (PTHrP) = malignancy

Question 25

A 72-year-old woman presents with weight loss and a 6-month history of cough. Her blood tests show a raised serum calcium. You suspect a diagnosis of lung cancer. What blood test result would support this diagnosis?

Answer 25

Low serum parathyroid hormone