Nephrolithiasis

Question 1

What is the urinary pH (normally) with uric acid stones?

Answer 1

pH <7

Question 2

What colour is the urine stained with hyperuricaemia?

Answer 2

Pink

Question 3

What is the rate of stone passage depending on the size of the stone?

Answer 3

<5mm: spontaneous, up to 95%
5-8mm: spontaneous passing rate 60-70%
>8mm: 10-20% spontaneously pass

Question 4

Radiolucent kidney stones

Answer 4

• Xanthine
• Uric acid

Occasionally cysteine and struvite

Question 5

What size stones may be missed on US?

Answer 5

Stones <3mm in size

Question 6

What you of stone is associated with theophylline?

Answer 6

Oxalate stones

Question 7

Amphotericin kidney stones?

Answer 7

Ca PO4

Amphotericin causes H+ back-leak and alkalisation of the urine.

Question 8

What type of stones are associated with allopurinol use? (directly)

Answer 8

Xanthine stones

Question 9

What is the management of cysteine stones?

Answer 9

• High fluid intake 3.5-5L/d
• Alkalinise the urine with 40-80mmol of K-citrate (get u pH >7)
• Reduce sodium and protein intake
• D-penillamine
• Tiopronin
• Captopril

Question 10

What is the genetics of cysteine stones?

Answer 10

• Autosomal recessive inheritance

Question 11

Wilson disease stones?

Answer 11

Cysteine stones

Question 12

Acetohydroxamic acid is a good treatment for patients with a sCr >2. True/False

Answer 12

False

Question 13

How is the urine alkalinised in hyperuricaemia?

Answer 13

K citrate

Question 14

What are the urea splitting organisms?

Answer 14

• Proteus
• Haemophilus
• Yersinia
• Klebsiella
• Serratia
• Citrobacter
• Staphylococcus
• Mycoplasma
• Pseudomonas

Question 15

What is a risk for hypocitraturia?

Answer 15

• Chronic metabolic acidosis

Question 16

What is the genetics for primary hyperoxaluria?

Answer 16

• Autosomal recessive

Question 17

What stone forming metabolic abnormality is associated with IBD/exocrine pancreas insufficiency?

Answer 17

• Ca Oxalate stones

- Undigested fatty acids bind to Ca