Chem Path: Clinical Chem CPC Flashcards
What electrolyte imbalance usually presents with depression?
Hypercalcaemia
What cardiac affect does hyperkalaemia have?
Asystole
What cardiac affect does hypokalaemia have?
VF
What does hypocalcaemia cause?
Nerve irritability which causes seizures
What is colle’s fracture?
Radial head displaced backwards (away from palm)
What is Smith’s fracture?
Caused by falling on flexed wrist - Radial head will be displaced forwards, towards the palm
What is Pott’s fracture?
Ankle fracture involving tibia and fibula
How does subacute bacterial endocarditis present?
Get lots of microemboli, splinter haemorrhages, splenomegaly and microscopic haematuria
How would acute rheumatic fever present?
Sore throat in childhood and then mount autoimmune antibodies
What is the first investigation you will do in someone with depression and renal stones?
Test calcium. If calcium is normal then no need to measure PTH
What are the 3 common causes of hyperCa
Malignancy
Primary hyperparathyroidism
Sarcoidosis
What investigation can distinguish between these?
PTH
How does hypercalcaemia present?
Moans, bones, groans, stones
Band keratopathy
Osteitis fibrosa et cystica
Pepper pot skull
Nephrocalcinosis
Pancreatitis
What kind of renal stones are the most common?
Calcium oxalate
Which stones cause gout and can they be seen on Xray?
Uric acid stones and they cannot be seen on x ray
How do you treat patients with hypercalciuria but without hypercalcaemia?
Thiazide diuretic
What organism grows with renal stones
Proteus mirabilis
Is all Vit D converted to 25 hydroxy vitamin D?
Yes, as all of them undergo first pass hepatic metabolism
How do you urgently manage hypercalcaemia
IV 0.9% saline, 1L over 1 hour
When would you give bisphosphonates for hypercalcaemia
Due to malignancy
What is the problem with bisphosphonates
They bind to calcium in the bone, and after operation, calcium falls really low.
What indicates urgent treatment for hypercalcaemia
Calcium of more than 3mmol/L
Why is hypercalcaemia above 3mmol/L dangerous?
Calcium is an osmotic diuretic and will cause polyurea leading to dehydration. Creatinine rises, and you have renal failure, leading to more dehydration. Then calcium rises even more giving rise to arrythmias
How do you manage hypercalcaemia beyond 3mmol/L
0.9% saline (dextrose if liver failure)
Furosemide if cannot give saline
IV pamidronate if its malignancy - prevent spread to bone and will cause Ca to fall after 4 days
How would you treat hyperparathyroidism?
fluid
avoid thiazide as they will increase plasma calcium concentration
Take out parathyroids
What can you see in the bone histology of PTH patients
Brown tumours - multinucleate giant cells
What would the hand x ray of a patient with long standing PTH show
Radial aspect cystic changes
Who would you expect to have looser’s zones
People with vit D deficiency
What is the hallmark of sarcoidosis
Non caseating granulomas
How does sarcoidosis lead to hypercalcaemia
Macrophages secrete 1 alpha hydroxylase which activates vit D and leads to hypercalcaemia
