calcium disorders Flashcards
what is the calcium sensing receptor?
it is a G protein coupled receptor that plays an essential part in regulation of extracelluar calcium homeostasis
what are the classic symptoms of hypercalcaemia?
Bones
Stones
Abdominal Groans
Psychic Moans
what are the acute symptoms of hypercalaemia?
Thirst
Dehydration
Confusion
Polyuria
what are the chronic symptoms of hypercalcaemia?
Myopathy
Fractures
Osteopaenia
Depression
Hypertension
Pancreatitis
DU
Renal calculi
what is the most common cause of hyprcalcaemia?
primary hyperthyroidism
then malignancy
what are less common causes of hypercalcaemia?
Drugs: Vit D, thiazides
Granulomatous Disease eg Sarcoid, TB
Familial Hypocalciuric Hypercalcaemia
High turnover: bedridden, thyrotoxic, Pagets
Others
Tertiary hyperparathyroidism
what is the first line investigation for hypercalcaemia?
parathyroid hormone level (PTH)
what are the criteria for a diagnosis of primary hyperparathyroidism?
Raised serum calcium
Raised serum PTH (or inappropriately normal)
Increased urine calcium excretion
Ensure Vitamin D replete
what occurs in malignancy to lead to hypercalcaemia?
Metastatic Bone destruction
PTHrp from solid tumours
Osteoclast activating factors
how is hypercalcaemia managed?
Fluids- rehydrate with 0.9% saline 4-6L in 24hours
Consider loop diuretics once rehydrated- avoid thiazides
Bisphosphonates- single dose will lower Ca over 2-3d, maximum effect at 1 week
Steroids occasionally used e.g Pred 40-60mg/day for sarcoidosis
does chemo reduce calcium in malignant disease?
yes
how is hypercalcaemia treated in sarcoidosis?
prednisolone
what is the main managements of primary hyperparathyroidism?
surgery (though not always required)
cinacalcet: Calcium Mimetic
Can be useful if need treatment, but
unfit for surgery
Approved for tertiary
hyperparathyroidism and
parathyroid carcinoma
what is primary hyperparathyroidism?
Primary overactivity of Parathyroid gland i.e adenoma
what are the biochemical markers of primary hyperparathyroidism?
high calcium
high PTH
what is secondary hyperparathyroidism?
Physiological response to low calcium or vit D
what are the biochemical markers of secondary hyperparathyroidism?
low calcium
high PTH
what is tertiary hyperparathyroidism?
Parathyroid becomes autonomous after many years of overactivity e.g renal failure
what are the biochemical markers of tertiary hyperparathyroidism?
high calcium
high PTH
what is chovsteks sign?
tapping over the facial nerve
what is trousseau sign?
carpopedal spasm
what are the causes of hypoparathyroidism?
Congenital absence (DiGeorge syndrome)
Destruction (surgery, radiotherapy, malign)
Autoimmune
Hypomagnesaemia
Idiopathic
what is the long term management of hypoparathyroidism?
Calcium supplement : > 1-2 g per day
Vitamin D Tablets:
1 alphacalcidol 0.5-1 mcg
(sometimes more)
Depot injection:
Cholecalciferol 300,000 units 6
monthly
what are the causes of hypomagnasaemia?
Alcohol
Drugs
Thiazide
PPI
GI illness
Pancreatitis
Malabsorption
