[8] Hypercalcaemia Flashcards
What are the causes of hypercalcaemia?
- Malignancy
- Primary hyperparathyroidism
- Sarcoidosis
- Vit D intoxication
- Thyrotoxicosis
- Side effect of lithium
What malignancies can cause hypercalcaemia?
- Bone mets
- Myeloma
- PTHrP secreting tumours
What are the symptoms of hypercalcaemia?
- Abdominal pain
- Vomiting
- Constipation
- Polyuria
- Polydipsia
- Depression
- Anorexia
- Weight loss
- Tiredness
- Weakness
- Hypertension
- Confusion
- Pyrexia
- Renal stones
- Cardiac arrest
What investigations are done in hypercalcaemia?
- FBC
- Protein electrophoresis
- CXR
- Isotope bone scan
- 24 hour urinary calcium excretion
What are the most common causes of hypercalcaemia?
Malignancy and hyperparathyroidism
What points towards malignancy as the cause of hypercalcaemia?
- Decreased albumin
- Decreased Cl-
- Alkalosis
- Hypokalaemia
- Increased phosphate
- Increased ALP
What indicates hyperparathyroidism as the cause of hypercalcaemia?
Increased PTH
What should the management of hypercalcaemia involve?
Diagnosis and treatment of the underlying cause
How should hypercalcaemia be managed if calcium is >3.5mmol/L and the patient is symptomatic?
- Correct dehydration with IV 0.9% saline
- Bisphosphonates
What do bisphosphonates do?
Prevent bone reabsorption by inhibiting osteoclast activity
How long does a single dose of bisphosphonates take to lower calcium?
2-3 days, with the maximum effect being achieved after a week
How should bisphosphonates be administered?
They should be infused slowly, for example 30mg in 300mL 0.9% saline over 3 hours
What are the potential side effects of bisphosphonates?
- Decreased phosphate
- Bone pain
- Myalgia
- Nausea
- Vomiting
- Headaches
- Lymphocytopenia
- Decreased magnesium
- Seizures
