Renal

Question 1

What is Bartter syndrome?

Answer 1

A group of disorders characterised by hypokalaemic metabolic alkalosis with hypercalciuria and salt wasting.

Question 2

What are the types of Bartter syndrome?

Answer 2

Antenatal (hyperprostaglandin E) - types I, II and IV.
More severe phenotype.
Classic - type III

Question 3

What is the pathogenesis of Bartter syndrome?

Answer 3

• defect in Na, Cl and K transport in the ascending LoH
• loss of Na and Cl result in volume contraction and stimulate renin-angiotensin II-aldosterone axis
• aldosterone promotes Na uptake and K secretion, exacerbating hypokalaemia
• aldosterone promotes H secretion distally worsening metabolic alkalosis
• Hypokalaemia promotes prostaglandin synthesis further activating renin-angiotensin II-aldosterone axis

Question 4

What is the use of a dimercaptosuccinic acid (DMSA) scan?

Answer 4

DMSA localises to the proximal tubules, assesses function, looks for scarring, and is generally done if there is evidence of VUR. Can be used to detect acute pyelonephritis and renal scarring in the acute and chronic settings, respectively.

Question 5

What is the use of a diuretic diethylene triamine pentaacetic acid (DTPA) scan?

Answer 5

DTPA is an excretory nuclear medicine scan, which assesses obstruction, used to assess differential renal function, and when frusemide is given, drainage/obstruction can also be measured.

Question 6

What is Gitelman syndrome?

Answer 6

Hypokalaemic metabolic alkalosis with hypocalciuria and hypomagnesaemia.

Question 7

What is the pathogenesis of Gitelman syndrome?

Answer 7

Defects in the NaCl cotransporter NCCT.

Question 8

Chronic use of which diuretic class gives a picture consistent with Bartter syndrome?

Answer 8

Loop diuretics

Question 9

Chronic use of which diuretic gives a picture consistent with Gitelman syndrome?

Answer 9

Thiazide diuretics

Question 10

What is the definition of nephrotic range proteinuria?

Answer 10

> 3.5g urinary protein/ 24h or Pr:Cr >2

Question 11

What glomerular lesions are associated with idiopathic nephrotic syndrome.

Answer 11

Minimal change disease (most common), focal segmental glomerulosclerosis, membranoproliferative glomerulosclerosis, C3 glomerulopathy and membranous nephropathy.

Question 12

What systemic diseases can cause secondary nephrotic syndrome?

Answer 12

SLE, HSP, malignancy (lymphoma and leukaemia) and infections (hepatitis, HIV and malaria).

Question 13

What blood findings do you see in obstructive uropathy?

Answer 13

• Hyperkalaemia.
• Metabolic acidosis.
• Likely due to a distal renal tubular acidosis with mineralocorticoid resistance.

Question 14

What is the classic triad seen in HUS?

Answer 14

• Thrombocytopenia, haemolytic anaemia, acute renal failure.

Question 15

What is the primary mechanism of renal injury in HUS?

Answer 15

• Endotoxin binding to renal vessel endothelium.
• Reserved to refer to the lipopolysccharide complex associated with the outer membrane of pathogens such as E. coli, Salmonella and Shigella.

Question 16

What are the pRIFLE criteria?

Answer 16

• Risk <0.5ml/kg/h for 8h.
• Injury <0.5ml/kg/h for 16h.
• Failure <0.3ml/kg/h for 24h or anuria for 12h.

Question 17

What fractional excretion of sodium suggests ATN?

Answer 17

• > 2.

Question 18

What urinary osmolality do you expect to see in ATN>

Answer 18

• <350

Question 19

Would you expect diuresis following fluid challenge in ATN?

Answer 19

• No. If no response to fluid challenge within 2h likely intrinsic or post-renal AKI.

Question 20

What is the fractional excretion of sodium used for?

Answer 20

• To differentiate between pre-renal and intrinsic AKI.

- Pre-renal <1%, intrinsic >2%, 1-2% undetermined.

Question 21

What is the triad seen in Denys Drash syndrome?

Answer 21

• Congenital nephropathy.
• Wilms tumour.
• Intersex disorders.
• Caused by WT1 mutation (tumour supressor).

Question 22

What are the features associated with Peirson syndrome?

Answer 22

• Congenital nephrotic syndrome.
• Occular abnormalities - microcoria, most are blind.
• Neurodevelopmental delay.
• Caused by changes in LAMB2 gene.