Calcium Disorders and Homeostasis Flashcards
how is serum calcium increased in the body?
bone reabsorption
gut absorption
under the control of PTH!
what does calcium sensing receptor do?
senses Ca, if high:
decreases PTH release from parathyroid gland
does vitamin D up or downregulate PTH?
upregulates
acute presentation of hypercalcaemia?
thirst
dehydration
confusion
polyuria
chronic presentation of hypercalcaemia?
"bones stones moans and groans" myopathy osteopaenia fractures depression hypertension abdo pain
main test for hypercalcaemia?
PTH
what would you suspect from:
high urea
high albumin
high Ca
dehydration
what would you suspect fro: high Ca normal albumin normal/high PTH low/normal phosphate increased urine Ca
primary hyperparathyroidism
what would you suspect from: high Ca normal albumin no PTH high phosphate
bone pathology
what bone pathology would present with high ALP?
bone mets
sarcoidosis
thyrotoxicosis
what bone pathology would present with low ALP?
myeloma
vit d excess
drug causes of primary hypoparathyroidism?
vit d
thiazides
what kind of hypercalcaemia does granulomatous disease cause?
primary
biochemical results for primary hyperparathyroidism:
serum Ca
serum PTH
urine calcium
raised
raised
raised
how should you treat someone with increased urine calcium?
ensure they’re vitamin d repleted
what biochemical results would indicate hypercalcaemia as a result of malignancy?
raised calcium
raised ALP
acute treatment for hypercalcaemia?
rehydrate with 0.9% saline 4-6l in 24hrs
what diuretic should be used for hypercalcaemia?
loop only
when would you do a parathyroidectomy for primary hyperparathyroidism?
end organ damage eg osteoporosis, renal stones
calcium >2.85mmol/l
age <50
define primary hyperparathyroidism
primary overactivity of the prathyroid glands eg adenoma
effect of primary hyperparathyoidism on PTH and Ca?
PTH = raised Ca = raised
effect of secondary hyperparathyroidism on PTH and Ca?
PTH = raised Ca = low
define secondary hyperparathyroidism?
physiological response to low calcium
define tertiary hyperparathyroidism?
parathyroid becomes autonomous after many years of secondary
effect of tertiary hyperparathyroidism on PTH and Ca?
Ca = raised PTH = raised
what genetic syndromes can be responsible for high calcium in the body?
MEN1
MEN2
FHPT
familial hypocalciuric hypercalcaemia
Ca reference range?
2.2-2.6mmol/l
what would be found on tests of hypercalciuric hypocalcaemia?
mildly high Ca
reduced urine Ca excretion
PTH mildly elevated
what would Ca, PTH, ALP and phosphate look like in someone with pagets?
Ca normal/high
PTH normal
ALP high
phos normal
what would, Ca, PTH, ALP and phosphate look like in someone with osteomalacia?
Ca very low
PTH normal
ALP increased
phosphate low
what would Ca, PTH, ALP, phosphate look like in someone with hypoparathyroidism?
Ca very low
PTH very low
ALP normal
phosphate normal/high
what would Ca, PTH, ALP and phosphate in familial hypocalciuric hypercalcaemia look like?
Ca high
PTH normal/high
ALP normal
phosphate normal
what would Ca, PTH, ALP and phosphate in malignant hypercalcaemia look like?
Ca very high
PTH very low
ALP vv high
phosphate normal
what would Ca, PTH, ALP and phosphate in primary hyperparathyroidism look like?
Ca v high
PTH v high
ALP normal/high
phosphate decreased
symptoms of hypocalcaemia?
paraesthesia in fingers/toes/perioral muscle cramps and weakness fatigue bronchospasm fits
common ECG finding of someone with hypocalcaemia?
prolonged QT
causes of hypocalcaemia?
hypoparathyroidism
vitamin d deficiency
chronic renal failure
pancreatitis
emergency treatment of someone with hypocalcaemia?
IV calcium gluconate
what genetic syndrome is congenitally calcium deficient?
di george syndrome
what would you suspect in a young person with primary hyperparathyroidism?
genetic cause
how is hypocalcaemia managed?
> 1-2g per day
daily vitamin d tablets/injection every 6 months
why do you get hypocalcaemia along with hypomagnasaemia sometimes?
calcium release from cells is dependent on Mg
PTH release is inhibited when Mg is low
causes of hypomagnasaemia?
alcohol drugs Gi illness pancreatitis malabsorption
what drugs can cause hypomagnasaemia?
thiazide
PPI
what Ca and PTH levels indicate pseudohypoparathyridism? why are they like this?
low Ca
high PTH due to PTH resistance
what drugs can cause vitamin d deficiency?
anticonvulsants
what conditions represent vitamin d deficiency?
rickets
osteomalacia
kidney problems can cause vitamin d deficiency: T or F?
T, chronic renal failure can
does osteomalacia present with high or low calcium?
low
clinical presentation of osteomalacia?
dental problems
proximal myopathy
bony tenderness
how would you treat vitamin D resistant rickets?
phosphate
vit d supplements
