Nephrolithiasis*

Question 1

What is nephrolithiasis

Answer 1

@kidney = renal stones form
@renal pelvis to urethra = deposits

Question 2

What is the most common type of renal stone

Answer 2

Calcium oxalate stones
-Radio opaque envelopes

Question 3

What are the different types of renal stones

Answer 3

Calcium Oxalate - RO Envelope
Calcium phospate -RO wedge
Uric acid - RL Diamond
Cysteine - RO Hexagon MC UTI
Struvite - RO Prism

Question 4

What are the RF for nephrolithiasis

Answer 4

Dehydration
Primary Kidney disease
Hyperparathyroid w/Hypercalcemia and hypercalciuria
UTI and stones
Hx of renal stones (Common for recurrence)

Question 5

What is the patholgy of renal stones

Answer 5

Excess solute in collecting duct= saturated urine = crystallisation
Stone obstructs outflow (Hydronephrosis)
Prostoglandin release occurs = dilation so more renal pelvis obstruction
Increase damage and infection risk

Question 6

how is hydronephrosis (Renal outflow obstruction) managed

Answer 6

Surgical decompression

Question 7

How does a patient present w/ nephrolithiasis

Answer 7

Loin to groin colic
Patient cant lay still
Haematuria and Dysuria
Fever if infection (pyelonephritis)

Question 8

What is a differential for pain that can be better with remaining still/guarding

Answer 8

Peritonitis = rigid patient

Question 9

Why may a patient with renal stones present with fever

Answer 9

Infections such as pyelonephritis

Question 10

What are the three most common sites of renal stones

Answer 10

PUJ (pelvo-uteric junction)
VUJ (Vagino-uteric junction)
PB (Pelvic brim)

Question 11

How can renal stones be investigated

Answer 11

1st = KUB X ray
Gold = NCCT KUB
Bloods
-FBC
-Deranged U+E
Urine dipstick for UTI

Question 12

What is the first line investigation of renal stones

Answer 12

KUB XRAY

Question 13

What is the Gold standard investigation for Renals stones

Answer 13

NCCT KUB

Question 14

Why is a non contrast CT KUB the best investigation for renal stones

Answer 14

Rapid and specific
NO CONTRAST as contrast would need to be excreted by kidney = harmful
BUT…..
Radiation exposure from scan

Question 15

How are renal stones managed

Answer 15

Hydration w/ Diclofenac analgesia
ABx for UTI
Stones <5mm pass by urine
ESWL/PCNL/Uretoscopy if stone >5mm

Question 16

What are the 3 surgical interventions for Renal stones

Answer 16

ESWL (Endoscopic sound wave breaking of stone)
PCNL (Keyhole removal of stone)
Uretoscopy (Scope up ureter to remove stone)

Question 17

When should ESWL be used

Answer 17

If stones are 5-20mm

Question 18

When should PCNL be used

Answer 18

If stones are >20mm

Question 19

What drugs should be avoided with renal stones and why

Answer 19

Diuretics and fluid

Pain gets worse

Question 20

Which is the only radiolucent stone

Answer 20

Uric acid

Question 21

What is the most common stone found in UTI

Answer 21

Struvite

Question 22

what is the differential for nephrolithiasis

Answer 22

Peritonitis = still patient

Question 23

Why is KUB X ray used first for nephrolithiasis

Answer 23

Cheap and easy

Question 24

Why may a urine dipstick be used in nephrolithiasis

Answer 24

If the stone causes UTI especially struvite

Question 25

Why is nephrolithiasis more common in males than female

Answer 25

Testosterone increases oxalate levels

Question 26

What is the first line management for nephrolithiasis

Answer 26

Hydration and diclofenac