Hypercalcaemia Flashcards
Parathyroid Disorder
What is hypercalcaemia?
High calcium levels in the blood serum
What are the causes of excessive PTH secretion leading to hypercalcaemia?
(1) Primary hyperparathyroidism (adenoma or hyperplasia)
(2) Tertiary hyperparathyroidism
How does malignancy cause hypercalcaemia?
(1) bone metastases
(2) PTH-related protein secretion
(3) Osteoclast-activating factors from tumours
What are the classic symptoms of hypercalcaemia?
“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
What are the acute symptoms of hypercalcaemia?
Thirst, dehydration, confusion, polyuria
What are the chronic symptoms of hypercalcaemia?
(1) Myopathy
(2) Fractures
(3) Osteopenia
(4) Depression
(5) Hypertension
(6) Pancreatitis
(7) Duodenal ulcers
(8) Renal calculi
What ECG finding is associated with hypercalcaemia?
Shortened QT interval
J wave
What blood test abnormalities indicate primary hyperparathyroidism?
- Raised calcium
- Low phosphate
- Detectable or elevated PTH
What blood test abnormalities suggest malignancy-related hypercalcaemia?
- Raised calcium
- Undetectable PTH
- Raised alkaline phosphatase (ALP)
What are the key biochemical findings in familial hypocalciuric hypercalcaemia (FHH)?
- Mild hypercalcaemia
- Low urine calcium excretion
- Normal/high PTH
- Normal ALP
- High phosphate
How is acute severe hypercalcaemia managed?
- IV 0.9% saline (4-6L in 24 hours) for rehydration
- Consider loop diuretics
(after rehydration) to prevent calcium reabsorption - Bisphosphonates to inhibit bone resorption (effect in 2-3 days, max at 1 week)
- Steroids
(eg, prednisolone 40-60 mg/day)
in cases like sarcoidosis
When is surgery indicated for primary hyperparathyroidism?
(1) Calcium >2.85 mmol/L
(2) Age <50
(3) Reduced eGFR (<60 mL/min)
(4) End-organ damage
What is cinacalcet, and when is it used?
A calcium mimetic that reduces PTH secretion, used when surgery is not an option or in tertiary hyperparathyroidism/parathyroid carcinoma
How is malignancy-related hypercalcaemia managed?
Treat the underlying malignancy
Which type of lung cancer can cause hypercalcaemia through PTHrP release?
Squamous cell
What are the key adverse signs of severe hypercalcaemia?
- Cardiac arrhythmia
- Seizures/coma
- Dehydration
(acute kidney injury will often occur)
What are the key treatments in hypercalcaemia?
(1) IV fluid rehydration (0.9% saline)
(2) IV bisphosphonate as second line
(3) Consideration of furosemide/prednisolone/calcitonin as third-line treatments
What is the first line management of acute hypercalcaemia?
Aggressive IV fluids
What is the best test to assess bone related damage in the context of hypercalcaemia?
DEXA bone scan
Which drugs can cause hypercalcaemia?
Vitamin D
Vitamin A
Lithium
Thiazides
What level of hypercalcaemia requires urgent treatment regardless of symptoms?
Greater than 3.5 mmol/L
What does undetected PTH mean?
Undetected PTH (parathyroid hormone) means that the hormone level is so low that it is below the test’s detection limit
Possible causes of undetected PTH include what?
(1) Hypoparathyroidism
(underactive parathyroid glands)
(2) Autoimmune conditions
(3) Surgical removal of the parathyroid glands
(4) Very high calcium levels
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?
Chvostek sign (to do with nerves)
Perioral and extremity numbness Laryngospasm
Arrhythmia
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?
Parathyroid hormone-related peptide (PTHrP)
= malignancy
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?
Low serum parathyroid hormone
