w4 - calcium metabolism

Question 1

t.f low calcium inhibits PTH production

Answer 1

false

Question 2

hydroapatite que?

too mch?

Answer 2

mineralising building block of bone

too much? -ve feedback, no more inorganic phosphate

Question 3

anticonvulsants effect on kidneys

Answer 3

stops vit d absorption

Question 4

symptoms of hypercalcaemia

Answer 4

bones
stones
ab groans
psychic moans

Question 5

acute signs of hypercal

Answer 5

Thirst
Dehydration
Confusion
Polyuria

Question 6

chronic signs o/symptoms of hypercal

Answer 6

Myopathy
Fractures
Osteopaenia
Depression
Hypertension
Pancreatitis
DU
Renal calculi

Question 7

causes of hypercal

Answer 7

Drugs:  Vit D, thiazides
Granulomatous Disease eg Sarcoid, TB
Familial Hypocalciuric Hypercalcaemia
High turnover:  bedridden, thyrotoxic, Pagets
Others
Tertiary hyperparathyroidism

Question 8

3 things to iagnose hyperpara

Answer 8

raised serum Ca
raised serum PTH (or inapp. normal)
incr urine calcium excretion (ensure Vit D replete)

Question 9

hypercalcaemi can happen in malignancy, 3 ways

Answer 9

metastatic bone destructiin
PTHrp from solid tumours
osteoclast activating factors

diagnosed: raised ca and alkaline phosphatase, imagin, isotope bone scan

Question 10

acute tx of hypercal

Answer 10

fluids - rehydrate (0.9% saline 4-6L 24hr)

Consider loop diuretics once rehydrated- avoid thiazides
Bisphosphonates- single dose will lower Ca over 2-3d, maximum effect at 1 week
Steroids occasionally used e.g Pred 40-60mg/day for sarcoidosis

Salmon calcitonin- rarely used
Chemotherapy may reduce calcium in malignant disease e.g. myeloma

Question 11

when is sestamibi scan used

Answer 11

only if gonna remove parathyroid

Question 12

management of primary hyperparathyroidsm

Answer 12

surgery - not always required

Cinacalcet
Cacium Mimetic
Can be useful if need treatment, but unfit for surgery
Licensed, but not SMC approved
Approved for tertiary hyperparathyroidism and parathyroid carcinoma

Question 13

parathyroidectomy indicated when

Answer 13

End Organ Damage:
Bone disease (Osteitis Fibosa et cystica; brown tumours/  pepper pot skull)
Gastric ulcers
Renal stones
Osteoporosis

Very high Calcium (>2.85mmol/l)

Under age 50

eGFR < 60 mL/min

Question 14

Non-pulsatile delivery of any hormone will cause __ __of usual delivery

Answer 14

opposite effect

Question 15

t.f 2ndary hyperpara wil result in low calcium and high PTH

Answer 15

true

Question 16

tertiary hyperpara will cause high cal and low pth

Answer 16

false

high cal and pTH (like primary)

Parathyroid becomes autonomous after many years of overactivity e.g renal failure

Question 17

which genetic syndromes will cause hyperpars

Answer 17

men1/2

Question 18

signs and symptoms of hypocal

Answer 18

Paraesthesia - fingers, toes, perioral
Muscle cramps, tetany
Muscle weakness
Fatigue
Bronchospasm or laryngospasm
Fits
Chovsteks sign (tapping over facial nerve)
Trousseau sign (carpopedal spasm)
=

Question 19

QT prolongation is seen in hypocal t.f

Answer 19

true

Question 20

emergency treatment for acute hypocal

Answer 20

Emergency: IV calcium gluconate 10 ml, 10% over 10 mins (in 50ml saline or dextrose)

Infusion (10ml 10% in 100 ml infusate, at 50 ml/h)

Question 21

congential absence of hypopara

Answer 21

digeorge syndrom

Question 22

long term management of hypopara

Answer 22

Calcium supplement : > 1-2 g per day
Vitamin D Tablets:
1 alphacalcidol 0.5-1 mcg (sometimes more)
Depot injection: Cholecalciferol 300,000 units 6 monthly

Question 23

how does hypomagnasaemia cause hypopara

Answer 23

Calcium release from cells is dependent on magnesium
In magnesium deficency intracellular calcium is high
PTH release in inhibited
Skeletal and muscle receptors less sensitive to PTH
If low replace with calcium and magnesium

Question 24

causes of hypomag

Answer 24

Alcohol
Drugs
Thiazide
PPI
GI illness
Pancreatitis
Malabsorption

Question 25

pseudohypopara

Answer 25

genetic defect leading to hypopara

Question 26

Pseudo-pseudohypoparathyroidism

Answer 26

Herditary Osteodystrophy

No alteration in PTH action and thus
Normal calcium

Question 27

pain described in osteomalacia

Answer 27

deep bony ache

Question 28

loosers zones

Answer 28

weak bne
neck of femur
sign on imaging

Question 29

2 big things chronic renal disease will causeq

Answer 29

vit d def

2ndary hypopara

Question 30

t.f chronic renal will have low 25-OH Vit d

Answer 30

false
high
but cant change to 1-25OH vitD

Question 31

another name for vitd -resistant rickets

Answer 31

x-linked hypophosphataemia