Nephrolithiasis* Flashcards
What is nephrolithiasis
@kidney = renal stones form
@renal pelvis to urethra = deposits
What is the most common type of renal stone
Calcium oxalate stones
-Radio opaque envelopes
What are the different types of renal stones
Calcium Oxalate - RO Envelope
Calcium phospate -RO wedge
Uric acid - RL Diamond
Cysteine - RO Hexagon MC UTI
Struvite - RO Prism
What are the RF for nephrolithiasis
Dehydration
Primary Kidney disease
Hyperparathyroid w/Hypercalcemia and hypercalciuria
UTI and stones
Hx of renal stones (Common for recurrence)
What is the patholgy of renal stones
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
how is hydronephrosis (Renal outflow obstruction) managed
Surgical decompression
How does a patient present w/ nephrolithiasis
Loin to groin colic
Patient cant lay still
Haematuria and Dysuria
Fever if infection (pyelonephritis)
What is a differential for pain that can be better with remaining still/guarding
Peritonitis = rigid patient
Why may a patient with renal stones present with fever
Infections such as pyelonephritis
What are the three most common sites of renal stones
PUJ (pelvo-uteric junction)
VUJ (Vagino-uteric junction)
PB (Pelvic brim)
How can renal stones be investigated
1st = KUB X ray Gold = NCCT KUB Bloods -FBC -Deranged U+E Urine dipstick for UTI
What is the first line investigation of renal stones
KUB XRAY
What is the Gold standard investigation for Renals stones
NCCT KUB
Why is a non contrast CT KUB the best investigation for renal stones
Rapid and specific
NO CONTRAST as contrast would need to be excreted by kidney = harmful
BUT…..
Radiation exposure from scan
How are renal stones managed
Hydration w/ Diclofenac analgesia
ABx for UTI
Stones <5mm pass by urine
ESWL/PCNL/Uretoscopy if stone >5mm
What are the 3 surgical interventions for Renal stones
ESWL (Endoscopic sound wave breaking of stone)
PCNL (Keyhole removal of stone)
Uretoscopy (Scope up ureter to remove stone)
When should ESWL be used
If stones are 5-20mm
When should PCNL be used
If stones are >20mm
What drugs should be avoided with renal stones and why
Diuretics and fluid
Pain gets worse
Which is the only radiolucent stone
Uric acid
What is the most common stone found in UTI
Struvite
what is the differential for nephrolithiasis
Peritonitis = still patient
Why is KUB X ray used first for nephrolithiasis
Cheap and easy
Why may a urine dipstick be used in nephrolithiasis
If the stone causes UTI especially struvite
