Nephrolithiasis Flashcards
What is nephrolithiasis?
Renal stones are kidney/uteric
Calcium oxalate stones forming in collecting duct, deposited anywhere from renal pelvis to urethra
Aetiology ?
who is most affected by it?
More in males slightly
Uncommon in children
20-40 y/o
very common
RF ?
Chronic dehydration
Kidney 1^ diseases (eg. PKD)
HyperPTH (hypercalcemia and hypercalcinuria)
UTI’s
History of previous stone
Pathology of renal stones?
Excess solute in CD, Supersaturated urine = favours crystallisation
Stones cause regular outflow obstruction - hydronephrosis (comp = requires surgical decompression ASAP)
Dilation + obstruction of renal pelvis (increased damage + infection risk)
What does obstruction cause release of?
prostaglandin release = results in natural diuresis
Sx?
Loin to groin pain, unilateral, that is colicky (peristaltic waves)
Px can’t lie still
Haematuria (blood in urine) + dysuria (pain while urinating)
What is a DDx for these Sx especially can’t lie still?
Peritonitis
Inflammation of lining of abdo - rigid
Do diuretics and fluids ease the pain?
No, make it worse
What does a fever suggest?
Superimposed infection eg. pyelonephritis
What Dx and Ix need to be done?
1st line = KUB (kidney, ureter, bladder) Xray - 80% specific for renal stones, cheap and easy
Gold standard = NCCT (non contrast CT) KUB - 99% specific for stones therefore DIAGNOSTIC
+ bloods - FBC, U+E (deranged suggest hydronephrosis), urine dipstick (UTI), Urinalysis (haematuria, pregnancy test)
Why is contrast not used?
Contrast would need to be excreted by kidney = harmful
Never do contrast if suspected kidney disease
Pros and cons of NCCT?
Pros = Rapid
Cons = each scan - around 18 month background radiation
Tx?
Symptomatic = Hydrate, analgesia eg. Diclofenac (NSAID) IV for severe pain
Abx for UTI (eg. gentamicin for pyelonephritis)
What happens to stones <5mm?
Stones pass spontaneously if small enough
What happens if bigger than 5mm?
Surgical elective Tx if too big to pass and causing pain
ESWL/PCNL
