Chem path 12 - clin chem CPC

Question 1

What are hyper and hypocalcaemia associated with?

Answer 1

Hypo –> irritability, fits

Hyper –> depression and tiredness

Question 2

Mycoardium in hyper and hypokalaemia

Answer 2

Hypo –> arrhythmias (unstable myocardium)

Hyper –> asystole (ultimate stable rhythm)

Question 3

Colles fracture vs smith’s fracture

Answer 3

Colles –> dorsal displacement/dinner form deformity, falling on outstretched hand
Smith’s –> Ventral displacement (Towards palm), falling on a flexed wrist (much rare)

Question 4

What does uraemia cause?

Answer 4

Tiredness

Question 5

What is a Pott’s fracture?

Answer 5

Ankle fracture involving the tibia and fibula

Question 6

How can you differentiate between renal stones and glomerulonephritis?

Answer 6

Glomerulonephritis is painless and produces microscopic haematuria whereas stones –> macroscopic

Question 7

How would you investigate renal stones?

Answer 7

CT-KUB/plain abdo X ray

Question 8

Next step after detecting renal stones on CT-KUB?

Answer 8

Measure plasma calcium (always do this before PTH as cannot interpret PTH isolated)

Question 9

Commonest cause of hypercalcaemia in hospitals

Answer 9

Cancer

Question 10

Commonest cause of hypercalcaemia in the community?

Answer 10

Primary hyperparathyroidism

Question 11

PTH and Ca in sarcoidosis

Answer 11

High Ca, low PTH

Question 12

PTH and Ca in cancer

Answer 12

High Ca, high PTH in hypercalcaemia of malignancy due to PTHrp or invading bone cancer

Question 13

Main cause of hyperparathyroidism

Answer 13

Adenoma

Question 14

What are the actions of PTH

Answer 14

Kidney: increases 1a hydroxylation –> vitamin D activation (calcitriol) –> gut to increase calcium and phosphate reabsorption
Directly resorb calcium
Directly excrete phosphate

Bone: increase osteoclast activity

Question 15

What condition is multiple parathyroid adenomas associated with?

Answer 15

MEN 1

Question 16

Which stones are opaque and which are radiolucent?

Answer 16

Calcium stones = opaque

Urate stones = radiolucent

Question 17

What presentation in the eye is associated with hypercalcaemia?

Answer 17

Band keratopathy (calcium deposition across teh front of eye, it is a feature of chronic hypercalcaemia so cannot be due to hypercalcaemia of malignancy)

Question 18

Complications of hypercalcaemia

Answer 18

Renal stones
Peptic ulcer disease
Pancreatitis
Skeletal changes
Osteitis fibrosa cystica (peper pot skull)

Question 19

Which bacteria commonly cause of recurrent infection in someone with renal stones?

Answer 19

Proteus mirabilis (loves calcium stones)

Question 20

Which stone is most common renal stone?

Answer 20

Calcium oxalate (second most common is calcium pyrophosphate)

Question 21

Management options for renal stones

Answer 21

Most will pass, use pain killers (PR diclofenac good)
Lithotripsy
Cystoscopy
Lithotomy

Question 22

Which diuretics prevent renal stones and which provoke?

Answer 22

Thiazide diuretics prevent calcinuria but increase serum calcium
Loop diuretics –> calciuria

Question 23

When would you perform urgent management of hypercalcaemia?

Answer 23

Ca2+ >3.0mmol/L and pt unwell

Question 24

What is the acute management of hypercalcaemia?

Answer 24

IV 0.9% Saline (~3-6L in 24 hrs, 1st 1L given in 1 hour)
IV furosemide (Aid calciuresis)
Consider IV zaldendronate (bisphosphonate 30-60mg)

Question 25

What are some considerations with giving IV bisphosphonates to treat hypercalcaemia?

Answer 25

Takes about 1 week to take affect | Hold off to begin with as you cannot measure serum calcium and phosphate if you give them

Question 26

When would you definitiely give IV bisphosphonates when treating hypercalcaemia?

Answer 26

If it is hypercalcaemia of malignancy as bisphosphonates are v good at treating bone pain

Question 27

Saline is safe in treating most conditions except...

Answer 27

LIVER FAILURE, you have salt retention so you would prefer dextrose

Question 28

What is the non urgent management of hypercalcaemia?

Answer 28

Well hydrated Avoid thiazides (reduce calciruia but increase plasma calcium) Surgery (parathyroidectomy)

Question 29

What investigations are done before parathyroidectomy?

Answer 29

Technetium SESTA MIBI and USS If concordant, whole neck does not need to be opened up If not concordant, surgeon needs to view all 4 glands and take out largest

Question 30

What is a histological feature of longstanding undiagnosed hyperparathyroidism?

Answer 30

Brown tumours

Question 31

What are brown tumours?

Answer 31

Multinucleate giant cells, activated osteoclasts in the bone

Question 32

Seasonal hypercalcaemia can only be...

Answer 32

SARCOIDOSIS

Question 33

CXR of someone with sarcoidosis

Answer 33

Bilateral hilar lymphadenopathy

Question 34

Mechanism of hypercalcaemia in sarcoidosis

Answer 34

Lung macrophages express 1a-hydroxylase --> activate vitamin D Pts more likely to become hypercalcaemic during summer months

Question 35

3 ways to assess fluid status of pt

Answer 35

JVP CVP gold standard if in ITU Skin turgor, mucous membranes

Question 36

Whcih MEN syndromes can present with hypercalcaemia?

Answer 36

MEN 1 and MEN 2