CS: Endocrine And Renal

Question 1

3 causes for dilure urine with azotaemia

Answer 1

• insufficient nephrons (v no or function)
• ADH > hyposthenuria
• osmotic diuresis

Question 2

What 2 opposing factors affect HR?

Answer 2

• K+ -> bradycardia

- sympathetic tone d/t hypovolaemia -> tachycardia

Question 3

What systemic diseases can cause v Na. What effect does this have?

Answer 3

Hypoadrenocorticism (Addisons) d/t loss of aldosterone

- cant concentrate urine as medullary tonciity gradient not strong enough

Question 4

Is azotaemia proportional to dilutionof the urine?

Answer 4

NO
- unless structural kidney damage
- azotaemia related to glomerular filtration
- dilution/concentration related ot tubular function
> one can be imparied without the other

Question 5

If azotaemic with hyposthenuria, what is the cause of the azotaemia?

Answer 5

Must be PRE-RENAL becasue hyposthenuria indicates tubules are functioning

• insufficient GFR to remove all azotaemia
• but filtrate that gets through is diluted

Question 6

Management of short term addisonian crisis

Answer 6

> proportion of shock dose fluids 80-90ml/kg/hour
manage hyperkalaemia
- calcium gluconate
- transcellular shifts (sodium bicarb, insulin and dextrose IV)
- ECG, serum K + and urine output monitoring
correct Na
- not too quickly as can -> myelinolysis and neuro signs, and destruction of other tissues d/t osmotic balance

Question 7

Should Addisons be tested commonly?

Answer 7

Test even if very low suspicion of disease - lethal disease but easy to tx

Question 8

Tx hypoadrenocorticism

Answer 8

> Fludrocortisone
- greatest MC component 
- Need to replace GC and MC 
- give parenterally initially until GIT settled then oral 
> Pred
- little MC activity (5: 0.2) 
> cortisol (1:1)

Question 9

Px Addisons

Answer 9

• If crisis controlled then excellent

- BUT will need lifetime tx

Question 10

See DL notes for table of case studies

Answer 10

• GFR
• USG hypo/iso/concentrated
• USG approprtiate?
• azotaemia
  > acute/chronic
  > pre/renal/post
  > reversible?