Clinical Chemistry Cases - Calcium Flashcards
Which of the following commonly presents with depression?
A) Hyperkalaemia B) Hypokalaemia C) Hypercalcaemia D) Hypocalcaemia E) Uraemia
A) Hypercalcaemia
Hypocalcaemia can give fits
Potassium gives cardiac issues, hypo gives arrythmias, hyper can give asystole
Depressed, bone fracture, followed by large haematuria
Cause of haematuria?
A) DKA B) Glomerulonephritis C) Acute rheumatic fever D) Subacute bacterial endocarditis E) Renal stones
E) Renal stones - Will give frank haematuria
Glomerulonephritis gives painless haematuria
Acute rheumatic fever is in kids
Subactute bacterial endocarditis gives microscopic haematuria
How should you investigate renal stones?
A) arterial blood gases B) renal biopsy C) plain abdominal X-ray D) abdominal ultrasound E) echocardiogram
C) Plain abdo x ray
CTKUB should be first line, but plain abdominal x ray will catch 85% of stones, so bets answer in this case
Depression, Fractures, Renal Stones
What test to do now?
A) Arterial blood gases B) Fasting glucose C) Plasma calcium D) Plasma PTH E) Plasma vitamin D
C) Plasma calcium
PTH can’t be interpreted without a calcium
Most people will have a low vit D
Hypercalcaemia
3 differentials
Cancer - Most common in hospital
Primary Hyperparathyroidism - Most common in general population
Sarcoid
What test to distinguish Cancer, PHPTH, or sarcoid, in Hypercalcaemia?
A) PTH B) Vit D C) Bone scan D) CXR E) CT thorax
A) PTH
Hypercalcaemia and Normal PTH
Most likely diagnosis?
A) Cancer
B) Primary hyperparathyroidism
C) Sarcoidosis
B) Primary hyperparathyroidism
PTH should be low or near 0 if not a PTH cause
3 ways cancer causes hypercalcaemia?
- Humoural Hypercalcaemia of malignancy - Some Cancer cells e.g. SCLC release PTHrP (Parathyroid Hormone related protein) causing bone breakdown
- Bone metastases - Some cancers e.g. Breast, invade bone and breakdwon of bone leads to calcium release
- Haemotological malignancy - Some cancers release cytokines which causes Calcium release
What needs to be done urgently for hypercalcaemia?
Normal saline
1 litre in the first hour to rehydrate someone who is dehydrated
Overall 4-6 litres in 24 hours
If older, give with some ferusamide to prevent overload
What needs to be done non urgently in PHPTH hypercalacemia
Arrange surgery
Hand bone X-Ray of PHPTH patient?
A) Normal B) Looser’s zones C) Ulnar aspect cystic changes D) Radial aspect cystic changes E) Changes in random carpal bones
D) Radial aspect cystic changes
Loosers are in Vit D deficiency
Bone histology changes in PHPTH?
A) Normal
B) Brown tumours
C) Multinucleate giant cells
D) No idea
B) & C)
Brown tumours are made of multinucleate giant cells
45 year old Afrocaribean man presents with dyspnoea.
Which is the most helpful investigation ?
A) Full blood count B) Urea and electrolytes C) Chest X-ray D) ECG E) echocardiogram
C) Chest X-ray
All are helpful, bu chest X ray is most useuful
45 year old Afrocaribean man presents with dyspnoea.
What would the X ray probably show?
Bi Hilar Lymphadenopathy
45 year old Afrocaribean man presents with dyspnoea
What would the histological finding probably?
Non caseating granulomas
