Hypercalcaemia

Question 1

normal serum control

Answer 1

40% is bound to albumin therefore inactive

2.2-2.6 (inc albumin)

Question 2

in acidotic states, is calcium increased or decreased?

Answer 2

increase ionised Ca, by reduced albumin binding

Question 3

in alkalotic states, is calcium increased or decreased?

Answer 3

decrease ionised Ca, by increased albumin binding

Question 4

how is calcium regulated?

Answer 4

diet: gut absorption (vit D)
bones: 99% of Ca
kidneys

Question 5

how is calcium linked to phosphate?

Answer 5

decrease Ca = increase phosphate

Question 6

what hormones are involved in calcium regulation?

Answer 6

PTH (chief cells)
calcitonin (thyroid)
vit D (gut)

Question 7

when is PTH secreted?

Answer 7

PTH is secreted when:
Ca is LOW
vit D is LOW
phosphate is HIGH

Question 8

how does calcitonin regulate Ca?

Answer 8

secreted by parafollicular/C cells of thyroid
acts to decrease Ca by antagonism of effects of PTH on bone
PTH/vit D levels are adjusted in response to calcitonin levels

Question 9

how does PTH regulate Ca?

Answer 9

bone: stimulates Ca REABSORPTION
kidney: renal tubular Ca ABSORPTION
GI: indirectly stimulating GI Ca ABSORPTION by INCREASING vit D activation by the kidney
increases renal phosphate EXCRETION

Question 10

when is vit D secreted?

Answer 10

when Ca is LOW

Question 11

when is calcitonin secreted?

Answer 11

when Ca is HIGH

Question 12

causes

Answer 12

97% primary hyperparathyroidism (high PTH) or malignancy (low PTH)
Renal insufficiency (tertiary hyperPTH)
HyperPTH (primary)
Iatrogenic (AdCal - OP supplement)
Neoplasms
Other endocrinopathies (Addisons)
Sarcoidosis

Question 13

signs and symptoms

Answer 13

Bones: pain, fractures
Stones: renal calculi, polyuria, polydipsia
Groans: high Ca, low gut motility, abdo pain
Psychiatric moans: confusion, headaches, convulsions, coma, death