6 - Urologic Stone Disease Flashcards
Inhibitory substances such _________ can prevent crystal precipitation and stone formation
Citrate
Magnesium
Struvite stones are associated with:
Urea-splitting bacteria
- proteus
- klebsiella
- staph aureus
- providencia
- corynebacterium
MCC of staghorn calculi?
Struvite stones
What are staghorn calculi
Large stones that form a cast in the renal pelvis
Does ABX work for staghorn?
No, shitty penetration
Its a massive stone filling in the renal pelvis / calyx thing
Risk factors for kidney stones:
Slide 8
Pain for stones due to
Obstruction of the Hollow viscous organ (ureter) and subsequent hydronephrosis creating pressure against Gerota’s fascia, causing flank pain
Isolated small renal pelvis stones (not staghorn). - pain?
No, not unless they cause intermittent obstructiobn
Why no serum create rise in acute obstruction?
Kidney’s are amazing and can operate 185% of baseline
If serum creat is high, suggests solitary kidney or pre-existing renal dz
Where does the stone get caught?
- UPJ (uretopelvic junction)
- Pelvic brim
- UVJ (ureteroviscal junction)
98% of stones less than 5mm
Will pass within 4 weeks without intervention
Stone greater than 7mm?
Have the urologist come down to the ED
Stone between 5 and 7mm
Can be seen outpatient
Less than 5mm?
Outpatient, PCM
Big reason to admit?
Pain
They’ve still got a good kidney, they’re just being admitted for pain control
Is hematuria required for the dx of stones?
No, but along with other sxs, it provides a high index of suspicion
Two mimickers for stones you must exclude:
AAA
Renal artery infarction
MC misdiagnosis given to patients with a rupturing or expanding AAA?
Nephrolithiasis
Stones don’t usually present in:
Dudes over 60
Stones also don’t cause HOTN, even transiently
Risk factors for poor outcomes
Slide 15
Female with suspected kidney stone?
Don’t forget to r/o pregnancy / possible ectopic
Check the urine for
Blood
Infection
All kids with stone
Send culture
CT for stones?
CT without contrast - study of choice
If we use contrast, can’t see the stone
Plain films?
90% of stones are radiopaque
Ultrasound for stones?
Not great - easy to miss stones under 5mm
But you can see bigger ones, or maybe discover another problem
Txt for stones
Pain control
Nausea control
ABX if signs of infection
Medical expulsion therapy (NSAIDs, alpha blockers)
IV fluids make no difference - just drink water if you’re not throwing up
Primary choice of analgesics for stones?
NSAIDs
Who shouldn’t get NSAIDs
ASA or NSAID sensitivity
Coagulopathy
GI bleeding risk
Renal impairment
Pt with a stone and signs of pyelo?
IV ABX and admit
Steroids for stones?
No
Slide 35
Indications for admission
Most of it pretty obvious
Pt has stones and only one kidney?
Auto-admission
Pts with hematuria, (-) imaging studies, and no other source require:
Outpatient urologic follow-up
Up to 30% of children with stones have:
Urinary tract anomalies
When you get a bladder stone?
Urine trouble!!!
