Renal stones

Question 1

What are some other names for renal stones?

Answer 1

Renal calculi
Urolithiasis
Nephrolithiasis

Question 2

Where do kidney stones form?

Answer 2

Renal pelvis

Question 3

What are the 2 key complications of renal stones?

Answer 3

Obstruction (leading to AKI)
and infection (obstructive pyelonephritis)

Question 4

What types of kidney stones are there?

Answer 4

Calcium oxalate
Calcium phosphate
Uric acid
Struvite (produced by bacteria)
Cystine

Question 5

What is a staghorn calculus?

Answer 5

When the kidney stone forms in the shape of the renal pelvis with “horns” extended into the renal calyces

Question 6

What is the presenting complaint in symptomatic kidney stones?

Answer 6

Renal colic (loin to groin pain that comes in waves)

Question 7

Renal colic is unilateral l___ to g___ pain that can be excruciating.
Colicky (fluctuating in severity) as the stone moves and settles.

Answer 7

loin to groin

Question 8

What are other signs of kidney stones along with renal colic?

Answer 8

Haematuria
N&V
Reduced urine output
Symptoms of sepsis if infection present.

Question 9

What investigations are there for kidney stones?

Answer 9

Abdominal X-ray (1st line, won’t show uric acid stones)

Non-contrast CT KUB (kidney, ureters, bladder) within 24 hours = gold standard

USS KUB

Urine dipstick:
Often shows haematuria, can exclude infection

Blood tests:
help show infection and kidney function. See if hypercalcaemia.

Question 10

How do you manage kidney stones?

Answer 10

NSAIDs for analgesia eg IM diclofenac

If NSAIDs not suitable, IV paracetamol.

Antiemetics eg metoclopramide

Antibiotics if infection present eg gentamycin

Watchful waiting for small stones

Tamsulosin can be used to help aid spontaneous passage of stones

For large stones, infection and complete obstruction, surgical intervention

Question 11

What surgical interventions are available for kidney stones?

Answer 11

Extracorporeal shock wave lithotripsy (ESWL) - shock waves break stones under x-ray guidance

Ureteroscopy and laser lithotripsy

Percutaneous nephrolithotomy (PCNL) - under general anaesthetic, nephroscope inserted through small incision in back, through kidney to assess ureter.

Open surgery

Question 12

Why would any CT scan need to be without contrast for suspected kidney stones?

Answer 12

The contrast needs to be excreted by teh kidney or is harmful, so shouldn’t be given in suspected kidney disease

Question 13

True or false: one episode of renal stones predisposes patients to further episodes

Answer 13

True

Question 14

What are NICE guidelines to advise patients to prevent repeat episodes of renal stones?

Answer 14

Increase oral fluid intake

Add fresh lemon juice to water (citric acid binds to urinary calcium reducing stone formation)

Avoid carbonated drinks (contain phosphoric acid promoting calcium oxalate)

Reduce dietary salt intake

Maintain normal calcium intake

Question 15

What medications can be give to reduce risk of recurrence for patients with calcium oxalate stones and raised urinary calcium?

Answer 15

Potassium citrate
Thiazide diuretics

Question 16

What are risk factors for renal stones?

Answer 16

Chronic dehydration
Primary kidney disease
Hyperparathyroidism
UTIs
History of previous renal stones

Question 17

True or false: Patients with renal stones can’t lie still

Answer 17

True

(note peritonitis: rigidity)

Question 18

What is hydronephrosis?

Answer 18

Swelling or dilation of the kidney due to the accumulation of urine

Question 19

B___ pain and frequent u____ are symptoms of hydronephrosis?

Answer 19

Back pain
Frequent urination

Question 20

Obstruction of renal pelvis causes release of _______ which results in natural diuresis causing increased frequency of urination

Answer 20

prostaglandin

Question 21

What age group is kidney stones most common?

Answer 21

20-40 y/o