renal stones

Question 1

what is the presentation of renal stones?

Answer 1

severe loin-to-groin pain

Question 2

what is the main composition of renal stones?

Answer 2

calcium oxalate

Question 3

which type of stone does crohns predispose to?

Answer 3

calcium oxalate

Question 4

what are the risk factors for renal stones?

Answer 4

Dehydration

Previous kidney stone

Stone-forming foods

Genetic: cystinuria (Dent’s disease; cysteine stones), renal tubular acidosis (calcium phosphate stones)

Systemic disease: Crohn’s disease (calcium oxalate stones)

Metabolic: hypercalcaemia, hyperparathyroidism, hypercalciuria (calcium stones)

Kidney disease-related: medullary sponge kidney, AD polycystic kidney disease

Drugs: loop diuretics and acetazolamide can cause calcium stones; protease inhibitors (HIV medication) cause radiolucent stones

Exposure: cadmium or beryllium

Other: gout and ileostomies (uric acid stones)

Question 5

what are examples of stone forming foods?

Answer 5

chocolate, rhubarb, spinach, tea, and most nuts are high in oxalate, and colas are high in phosphate

Question 6

what type of stones are formed in Dents disease?

Answer 6

cystine

Question 7

what type of stones are formed in renal tubular acidosis?

Answer 7

calcium phosphate stones

Question 8

which types of stones are present in gout?

Answer 8

uric acid stones

Question 9

what is an important differential to rule out when suspecting renal stones?

Answer 9

AAA especially in the elderly with new onset flank pain and no history of stones

Question 10

what is the gold standard diagnostic imaging?

Answer 10

non contrast CTKUB within 14 hours

Question 11

what is the management for kidney stones?

Answer 11

< 5 mm watchful waiting and conservative management with antiemtics like cyclizine and NSAIDS like IM diclofenac

> 5mm= surgery

1. lithotripsy
2. ureteroscopy
3. percutaneous nephrolithotomy

Question 12

which stones are associated with infection?

Answer 12

struvite-> produced by bacteria

Question 13

what is the inheritence of cystinuria?

Answer 13

autosomal recessive-> leads to formation of cystine stones

Question 14

which stones are not visible of XRAY?

Answer 14

uric acid stones

Question 15

what are some lifestyle measures for reccurrent stone formers?

Answer 15

• increase oral fluid intake (2.5 – 3 litres per day)
• Add fresh lemon juice to water (citric acid binds to urinary calcium reducing the formation of stones)
• Avoid carbonated drinks (cola drinks contain phosphoric acid, which promotes calcium oxalate formation)
• Reduce dietary salt intake (less than 6g per day)
• Maintain a normal calcium intake (low dietary calcium might increase the risk of kidney stones)

Question 16

what are complications of kidney stones?

Answer 16

Obstruction and hydronephrosis: acute kidney injury and renal failure

Urosepsis: an infected, obstructing stone is a urological emergency and requires urgent decompression- using percutaneous nephrostomy

Question 17

what are complications of renal stones related to procedures?

Answer 17

Ureteric injury
Bleeding
Sepsis
ESWL haematoma