Clinical Calcium

Question 1

what is the normal serum calcium range

Answer 1

2.2-2.6mmol/l

Question 2

iatrogenic cause of hypocalcaemia

Answer 2

thyroid surgery that damages the parathyroid

radiotherapy of thyroid/head and neck

Question 3

deficiencies that cause hypocalcaemia

Answer 3

vitamin D, magnesium

Question 4

drugs that cause hypocalcaemia

Answer 4

cincalcet
calcium chelators
foscarnet
phenytoin
fluoride poisoning

Question 5

what does foscarnet treat

Answer 5

viral diseases

Question 6

how does foscarnet cause hypocalcaemia

Answer 6

it forms a complex with calcium

Question 7

what state of calcium is caused by hypoparathyroidism

Answer 7

low calcium

Question 8

features of pseudoparathyroidism

Answer 8

organs are resistant to PTH so PTH is high

low calcium and hairy hands

Question 9

what condition gives you hairy hands

Answer 9

pseudoparathyroidism

Question 10

true/false pancreatitis can cause hypocalcaemia

Answer 10

true

Question 11

true/false malignancy can cause hypocalcaemia

Answer 11

false - commonly in neoplastic syndrome the tumour secretes PTH i.e. hypercalcaemia

Question 12

hypo/hyper Ca2+ causes a prolonged QT interval

Answer 12

hypo

Question 13

cardiac presentation of hypocalcaemia

Answer 13

prolonged QT interval
hypotension
heart failure
arrhythmia
papilloedema

Question 14

what is Chovstek’s sign

Answer 14

face relaxed, tap facial nerve in front of earlobe and the mouth will twitch

Question 15

what is Chovstek’s sign a sign of

Answer 15

hypocalcaemia

Question 16

acute neuro presentation of hypocalcaemia

Answer 16

tetany
paraesthesia
carpopedal spamsm
Chovstek's sign
Trousseau's sign
laryngo/bronchospasm

Question 17

long term consequences of hypocalcaemia on nervous system

Answer 17

calcification of basal ganglia
parkisonisms
dementia

Question 18

important things to ask on history in hypocalcaemia

Answer 18

diet (calcium and vit D)
neck surgery
autoimmune disorders
medications that may interfere with Ca2+
FH

Question 19

significance of checking magnesium in suspected hypocalcaemia

Answer 19

magnesium is permissive to PTH and needed for it to have its effect. Therefore low Ca2+ could be caused by magnesium deficiency

Question 20

high urea and creatinine would be seen in hyper/hypo

Answer 20

hypocalcaemia

Question 21

process of 4 blood investigations

Answer 21

1. check serum calcium
2. check PTH
3. a if high check magnesium
4. b if low check urea/creatinine
5. b if urea/creatinine normal check vitamin D

Question 22

treatment of mild hypocalcaemia

Answer 22

oral calcium, vit D or magnesium as appropriate

Question 23

what level constitutes hypercalcaemia

Answer 23

> 2.6mmol/l

Question 24

what is MEN

Answer 24

Multiple Endocrine Neoplasia inheritied syndrome

Question 25

MEN is a cause of what

Answer 25

primary hypercalcaemia

Question 26

sarcoid, TB, histioplasmosis and wegener's all cause hyper/hypocalaemia

Answer 26

hypercalcaemi

Question 27

drugs that cause hypercalcaemia

Answer 27

``` thiazide diuretics lithium teriparatide vitamin A theophylline toxicity ```

Question 28

acromegaly can cause hypo/hypercalcaemia

Answer 28

hypercalcaemia

Question 29

two biggest causes of hypercalcaemia

Answer 29

primary hyperparathyroidism (community) and malignancy (hospital)

Question 30

adrenal insufficiency will cause serum calcium to increase/decrease

Answer 30

increase

Question 31

true/false - being inactive can induce hypercalcaemia

Answer 31

true - loss of stimulus to build bone so Ca2+ broken down from it into plasma

Question 32

what does "bones, stones, groans and psychic moans" refer to

Answer 32

the presentation of hypercalcaemia

Question 33

key presentation of hypercalcaemia

Answer 33

``` polyuria polydipsia kidney stones weakness and bone pain confusion and loss of concentration nausea and vomiting constipation short QT interval ```

Question 34

hyper/hypocalcaemia causes a short QT interval

Answer 34

hyper

Question 35

how does high calcium affect the QT interval

Answer 35

calcium sustains the plateau phase so when there is more calcium available this stage can happen faster giving a shorter QT interval

Question 36

malignancy is more indicative of hyper/hypocalcaemia

Answer 36

hypercalcaemia - common for tumours to secrete Ca2+

Question 37

process of blood investigations in hypercalcaemia

Answer 37

1. serum calcium 2. corrected calcium from removing drugs or accounting for low albumin 3. PTH

Question 38

low PTH with high Ca2+ suggests the cause is...

Answer 38

malignancy or a drug

Question 39

85% of primary hyperparathyroidism results from...

Answer 39

an adenoma of parathroids

Question 40

investigations is suspected primary hyperparathyroidism

Answer 40

Ca2+, PTH, U&Es Parathyroid US SESTAMIBI contrast scan for parathyroid uptake DEXA for osteoporosis

Question 41

indications for PT surgery

Answer 41

``` symptoms of hypercalcaemia Ca2+ >2.85 osteoporosis eGFR<60 kidney stones <50 y/o ```

Question 42

Give IV _____ and fluids in hypercalcaemia

Answer 42

IV biphosphonates