Renal stones

Question 1

What are renal stones

Answer 1

Nephrolithiasis, crystalline calculi within the urinary system

Question 2

What are risk factors for kidney stones

Answer 2

White men
Obesity
High protein and salt intake
Dehydration
Crystaluria 
Hyperparathyroidism
UTI with proteus mirablis

Question 3

What are different types of renal stone

Answer 3

Calcium e.g. oxalate or phosphate (hyperparathyoidism)

Struvite: caused by proteus, staghorn

Uric acid: metabolic syndrome

Others: cystine

Question 4

What are inhibitors of stone formation?

Answer 4

○ Citrate
○ Magnesium
○ Pyrophosphate
Glycoproteins

Question 5

What are Sx of renal stones?

Answer 5

Pain: severe loin-groin flank pain. Patients can’t sit still

Haematuria

Urinary frequency/urgency

Nausea and vomiting

UTI or sepsis

Can be incidental finding

Question 6

What are DDx for renal stones?

Answer 6

• Appendicitis
	• Ectopic pregnancy
	• Ovarian cyst
	• Bowel obstruction 
	• PUD
Ovarian or testicular torsion

Question 7

What Ix in renal stones?

Answer 7

Urinalysis: non-visible haematuria

(preg test)

Bloods: evidence of infection? Ca? Ur?

CTKUB: calcification in renal collecting system or ureter

Question 8

What is Rx in renal stones?

Answer 8

If infection, need urgent IV antibiotic and drainage (via stent of PC nephrostomy) to prevent urosepsis and death.

Conservative

Non-invasive

Invasive

Question 9

What is conservative Rx in stones/

Answer 9

Acute renal colic with <5mm stones, give hydration, NSAIDs e.g. diclofenac, and anti-emetics as they may pass.

Question 10

What non-invasive therapies for renal stones?

Answer 10

Alpha blockers e.g. tamsulosin can promote expulsion

ESWL: ureteric stones < 10mm or renal stones < 20mm. Shockwaves break stones.

Question 11

What invasive therapy for renal stones?

Answer 11

Ureteroscopy and removal

PCNL: stones > 20mm in kidney

Lap/open: huge ureteric stones, non-functioning kidney

Question 12

What long term Rx after renal stones

Answer 12

Hydration + diet modification. Less Na/protein, more citrus.

If uric acid stones, allopurinol

If calcium stones, thiazide diuretics and K citrate

If low citrate, Alkalinisation therapy with potassium citrate

If struvite, urease inhibitor

Question 13

What are complications of renal stones?

Answer 13

Infection and urosepsis
Retention

Surgery can cause haematoma, ureteric injury, ureteric stricture