Hypercalcaemia Flashcards
What are the 2 causes for 90% of hypercalcaemia?
- Hyperparathyroidism
- Malignancy
What are 7 less common causes of hypercalcaemia? ( There are more than 7 btw)
- High vitamin D
- Lithium
- Rhabdomyolyais
- Throtoxicosis
- Thiazides diuretics
- Adrenal insufficiency
- Phaeochromocytoma
- Sarcoidosis
High Calcium + High PTH OR PTH that is normal but >median reference range =?
Primary or Tertiary Hyperparathyroidism
High Calcium + Low PTH =?
Malignancy or other rare cause
What are 7 common symptoms?
- Polyuria
- Thirst
- Mood disturbances and confusion
- Renal impairment
- Arrythmias
- Pancreatitis
- Muscle weakness
Is peri oral tingling a sing of hypercalcaemia or hypocalcaemia?
Hypocalcaemia
What questions should you ask about the patient’s history if they have hypercalcaemia?
- Symptoms of hypercalcaemia
- Symptoms of Malignancy- weight loss, night sweats, cough
- Family history
- Drugs including supplements, OTC preparations.
What should you do on examining the patient with hypercalcaemia?
- Assess for cognitive impairment
- Look for underlying causes of malignancy – Respiratory, abdomen, breasts, lymph nodes.
What does the clinical picture look like in secondary hyperparathyroidism?
They will have a high PTH but will have a normal although calcium level.
The cause of secondary hyperparathyroidism is usually due to kidney, liver or bowel disease.
After rehydration, What are the common tests that should be done?
- U&Es
- Albumin
- PTH
- Myeloma screen
- 25-OH vitamin D concentrations
Describe the algorithm for investigating hypercalcaemia.
Describe the normal calcium regulatory pathway
- Low blood calcium levels stimulate PTH release.
-
PTH release causes an overall increase in Calcium and a decrease in PO43-
- Main function of PTH: Kidneys: It increases calcium and decreases PO43-.
- Bones: It increases osteoclast activity - which releases calcium and PO43-
- Stimulates the production of calcitriol.
-
Calcitriol (Vitamin D that has been produced by the Liver and then activated by the kidneys)
- Main function: Intestines: Increases Absorption of calcium and PO43-.
- Inhibits PTH.
- And thus Blood Calcium Increases. (PO43- generally decreases)
Describe the normal calcitonin regulatory pathway.
- High Blood Calcium levels
-
Calcitonin is released by C-Cells in the Thyroid gland.
- Bones: It increases calcium and PO43- deposition in bones.
- Kidneys: It increases excretion of calcium in kidneys.
- Intestines: Decreases calcium gut absorption.
- And thus, Calcium levels are lowered.
Are low or high phosphate levels of significance?
Hypophosphateaemia - is of little significance. Can be low in hyperparathyroidism.
Hyperphophataemia - commonly due to CKD.
What is the management for hypercalcaemia?
- Rehydration (3-4 litres a day)
- Bisphosphonates - take 2 to 3 days to work and reach maximal effect by 7 days.
- Other options
- Calcitonin - quicker than bisphosphonates.
- Steroids in sarcoidosis
A 70-year-old woman is referred by a GP colleague to the hospital with a breast lump.
She is asymptomatic but her investigations reveal:
- Corrected calcium - 2.72 mmol/L (2.2-2.6)
- Phosphate - 0.80 mmol/L (0.8-1.4)
- Alkaline phosphatase - 110 U/L (45-105)
- PTH concentration - 5.1 pmol/L (0.9-5.4)
What is the most likely diagnosis?
- Boney Metastases
- Chronic Vitamin D excess
- Ectopic related peptide (PTHrp) secretion
- Multiple Myeloma
- Primary Hyperparathyroidism
Primary Hyperparathyroidism
- Boney mets and multiple myeloma could have high calcium but would then have a low PTH.
- Vitamin D Excess - would cause an elevated phosphate.
- Ectopic PTHrp secretion - Not usually detected as part of PTH. PTH would therefore be low but then if you test for PTHrp the PTHrp would be high.
..Describe another algorithm using albumin, phosphate and ALP.
