Wed1September0557PM 3

You have been called to the ward by the senior nurse, to review a repeat calcium result. The repeat result is 3.9 mmol/L (2.2-2.6), the previous result four hours earlier was 3.2.

The patient has a disseminated malignancy with an unknown primary.

Which of the following statements is most correct when considering the hypercalcaemia of malignancy?

(Please select 1 option)

A prolonged QT interval is associated with hypercalcaemia Incorrect answer selected

On neurological examination, hyporeflexia may be exhibited This is the correct answer

Bisphosphonates inhibit osteoblast function thereby lowering calcium

Calcitonin is of greater benefit than bisphosphonates in the treatment of hypercalcaemia of malignancy

NSAIDs are indicated for bone pain in this patient

Explanation

This is an oncological emergency affecting 20-40% of patients with advanced cancer.

Hyporeflexia is a common clinical sign in patients with significant hypercalcaemia.

Other signs include the classic mnemonic, "bones, stones, groans, and moans":

Bones - bone pain, especially if the PTH is elevated

Stones - renal calculi

Groans - constipation and likely subsequent abdominal pain

Psychic moans - depression and confusion

Nausea and vomiting, fatigue, and pancreatitis.

Electrocardiogram changes in hypercalcaemia include bradycardia, prolonged PR interval, short QT interval, widened T waves, and arrhythmias.

Bisphosphonates inhibit bone resorption by osteoclasts and are the first line pharmacological treatment of hypercalcaemia of malignancy. However, they take 3-4 days to reduce the calcium level and can result in worsening renal function. It is therefore critical to fully hydrate the patient prior to treatment; in clinical practice, we tend to give 3 litres of fluids over a 12-18 hour period prior to giving bisphosphonate. Clearly, this needs to be altered if the patient is at risk of fluid overload and cardiac failure.

Calcitonin use is limited by its association with anaphylaxis.

Non-steroidal anti-inflammatory drugs (NSAIDs) should not be prescribed in patients with hypercalcaemia as they reduce renal blood flow thus inhibiting urinary calcium excretion.

Answer Statistics

1

21%

2

26%

3

19%

4

20%

5

16%

Times answered: 275