Parathyroid disorders Flashcards
What mineral decreases parathyroid hormone secretion?
Calcium
What are some symptoms of hypercalcaemia?
Bones - Bone pain
Stones - Kidney stones
Abdominal groans - Constipation
Thrones - Polyuria
Psychiatric moans - Depression, anxiety
What are some acute signs of hypercalcaemia?
- Thirst
- Dehydration
- Confusion
- Polyuria
What are some chronic presentations of hypercalcaemia?
- Myopathy
- Fractures
- Osteopenia
- Depression
- Hypertension
- Pancreatitis
- Renal calculi
What is hypocalcuric hypercalcaemia?
This is an autosomal dominant, deactivating mutation in calcium sensing receptors
What are some presentations of hypocalcuric hypercalcaemia?
Mild hypercalcaemia
Reduced urine calcium excretion
Marginally elevated PTH
What are soem causes of hypercalcaemia?
Primary and tertiary hyperparathyroidism
Malignancy
Drugs
Granulomatous disease
Hypocalcuric hypercalcaemia
Milk-Alkali syndrome (Too many antacids)
MEN1/2
What are some drugs that can cause hypercalcaemia?
Vitamin D
Thiazides
What are the mechanisms of hypercalcaemia in malignancy?
Metastatic bone restructure, PTHrp release and osteoclast activating factor release by tumours causes increased release of bone stored calcium into the blood
How will hypercalcaemia of malignancy be diagnosed?
Raised calcium
Raised ALP
X-ray, CT, MRI or PET showing tumour
Isotope bone scanning
Give the cause of hypercalcaemia:
High/Normal PTH
High Urine Ca2+ excretion
Primary/Tertiary hyperparathyroidism
Give the cause of hypercalcaemia:
High/Normal PTH
Low urine Ca2+ excretion
Familial Hypocalcuric hypercalcaemia
Give the cause of hypercalcaemia:
Low PTH
High phosphate
Raised ALP (Bone pathology)
Metastases
Sarcoidosis
Thyrotoxicosis
Give the cause of hypercalcaemia:
Low PTH
High phosphate
Low ALP (No bone pathology)
Myeloma
Vitamin D toxicity
Milk-alkali syndrome
How should hypercalcaemia be acutely managed?
Fluids (0.9% saline 4-6L 24hours)
Consider loop diuretics (Not thiazides)
Bisphosphonates
Steroids possible (E.g. Prednisolone in sarcoidosis)
What are some causes of hypocalcaemia?
- Chronic kidney disease
- Congenital absence (DiGeorge syndrome)
- Destruction (surgery, radiotherapy, malignancy)
- Autoimmune
- Hypomagnesaemia - calcium release from cells is dependent on magnesium
- Idiopathic
- Pseudohypoparathyroidism and pseudo-pseudohypoparathyroidism
What are some symptoms of hypocalcaemia?
- Paraethesia - fingers, toes, perioral
- Muscle cramps, tetany
- Muscle weakness
- Fatigue
- Bronchospasm or laryngospasm
- Fits
What are some clinical signs of hypocalcaemia?
- Chovesteks sign - gentle tapping over the facial nerve causes twitching of the ipsilateral facial muscles
- Trousseau sign - inflation of the sphygmomanometer cuff above systolic pressure for 3 min induces tetanic spasm of the fingers and wrist
- ECG - QT prolongation
How is acute severe hypocalcaemia managed?
- IV calcium gluconate 10 ml, 10% over 10 mins (in 50ml saline or dextrose)
- Calcium infusion (10ml 10% calcium gluconate in 100ml infusate, at 50 ml/h)
How is hypocalcaemia treated in the long term?
- Calcium supplement >1-2g PO/day
- Vitamin D
- 1 alphacalcidol 0.5-1 mcg PO/day OR
- Depot injection: cholecalciferol 300 000 units 6 monthly
What is meant by primary hyperparathyroidism?
This is hyperparathyroidism caused by uncontrolled parathyroid hormone produced directly by a tumour of the parathyroid gland (E.g. Parathyroid adenoma)
What metabolic change will result from hyperparathyroidism?
Hypercalcaemia
How is primary hyperparathyroidism diagnosed?
Raised serum calcium
Raised serum PTH
Increased urine calcium excretion
How is primary hyperparathyroidism managed?
Surgical tumour removal
Symptomatic relief with cinacalcet (Calcium mimic)
