clinical calcium homeostasis

Question 1

dietary sources of calcium

Answer 1

milk, cheese other diary 
green leafy veg 
soya beans 
tofu 
nuts
bread 
fish where u eat bones

Question 2

functions of calcium

Answer 2

bone formation
cell division and growth
muscle contraction
neurotransmitter relase

Question 3

normal range calcium (adjusted)

Answer 3

2.2-2.6mmol/l

Question 4

how do we calculate free calcium

Answer 4

inc albumin decreases free calcium
dec albumin increases free calcium

adjust Ca2+ by 0.1mmol/l for each 5g/l in albumin from 40g/l

Question 5

sources of vitamin d

Answer 5

sun 
oily fish 
eggs 
fortified fat spreads
fortified breakfast cereals

Question 6

how are changes in ECF calcium levels transmitted to parathyriod cells

Answer 6

via calcium-sensing receptor

Question 7

hypocalcaemia

Answer 7

serum calcium <2.20

Question 8

hypocalcaemia - acute features

Answer 8

tetany 
parasthesia
muscle twitching 
Trousseau's sign 
Chovstek's sign 
seizures
laryngospasm
bronchospasm 
prolonged QT interval 
hypotension 
heart failure 
arrythmia

Question 9

hypocalcaemia - chronic features

Answer 9

extrapyramidal signs
parkinsonism 
dementia 
subcapsular cataracts
abnormal dentition 
dry skin

Question 10

when do symptoms of hypocalcaemia typically develop

Answer 10

serum calcium below 1.9

Question 11

Trousseau’s sign

Answer 11

hand curls up when pump up BP cuff

Question 12

Chovstek’s sign

Answer 12

twitching - spasm of facial muscles when tap facial nerve anterior to earlobe

Question 13

causes of hypocalcaemia

Answer 13

disruption PT gland
VitD def
Mg2+ def
cytotoxic drug induced hypocalcaemia
pancreatitis

Question 14

hypocalcaemia investigations

Answer 14

check PTH

if low (not right) check magnesium

if high (right) check urea and creatinine

Question 15

treatment hypocalcaemia: mild (>1.9)

Answer 15

oral calcium tablets

VitD if deficient
if low Mg2+, stop any precipitating drug and replace Mg2+

Question 16

treatment hypocalcaemia: severe <1.9

Answer 16

medical emergency

IV calcium gluconae

initial bolus (10-20ml 10% calcium gluconate in 50-00ml of 5% dextrose IV over 10min with ECG monitoring)

calcium gluconate infusion

treat underlying cause

Question 17

hypercalcaemia <3

Answer 17

often asymptomatic

Question 18

treatment hypercalcaemia: 3-3.5

Answer 18

may be well tolerated if risen slowly

prompt treatment usually indicated

Question 19

treatment hypercalcaemia: >3.5

Answer 19

requires urgent correction due to risk of dysrythmia and coma

Question 20

causes of hypercalcaemia

Answer 20

primary hyperparathyrpidism

malignancy

Question 21

clinical features of hypercalcaemia

Answer 21

bones, stones, groans and pelvic moans

polyruia, polydipsia
nephrolithiasis
anorexia
nausea
constipation 
muscle weakness
bone pain 
dec concentration 
short QT interval

Question 22

hypercalcaemia managemnet

Answer 22

rehydration

IV bisphosphonates