hypocalcaemia

Question 1

decreased serum calcium will result clinically in

Answer 1

increased membrane excitateability because calcium is responsible for stabilising the resting membrane potential of cells

Question 2

effect of parathyroid hormone is to

Answer 2

increase serum calcium
decrease serum phosphate

Question 3

effect of calcitriol on calcium

Answer 3

increase serum calcium
increase serum phosphate

Question 4

effect of calcitonin on calcium

Answer 4

decrease serum calcium
decrease serum phosphate

To remember that calcitonin keeps the calcium in the bones, think: Calci-bone-in!

Question 5

low calcium with low PTH may indicate

Answer 5

hypoparathyroidism
eg. following surgical removal of the parathyroid glands, autoimmune destruction, congenital disorders

Question 6

low calcium with high PTH

Answer 6

vit D deficiency
chronic kidney disease
pseudohypoparathryoidsim
hyperphostataemia eg. TLS, rhabdomyolysis, crush injury
acte necrotising pancreatitis ie. calcium soap precipitation in the abdomen

Question 7

other causes of hypocalcaemia

Answer 7

medications eg. loop diuretics, calcitonin, bisphosphonates, glucocorticoids
multiple blood transfusions
hypomagnesaemia
hyperventilation
osteoblastic mets

Question 8

hypoparathyroidism most commonly occurs due to

Answer 8

most commonly occurs as the result of accidental injury to parathyroids (or their blood supply) during thyroidectomy, parathyroidectomy, or radical neck dissection

autoimmunity is the second most common cause

Question 9

clinical features of hypoamgnesaemia

Answer 9

tetany, laryngoscpam, seizures
arrythmias

Question 10

treatment for hypoparathyroidism

Answer 10

vitamin and mineral supplementation with calcium, vitamin D, magnesium
PTH replacement therapy