Urolithiasis Flashcards
Nephrolithiasis:
- what is this?
- what are the 3 MC sites of obstruction?
- pathophysiology
What; stone in the kidney or ureters,
3MC sites: UPJ, where the ureter crosses the vasculature and right before entering the bladder.
Pathophys:
- supersaturation of urine by stone-forming constituents, including calcium, oxalate, and uric acid.
- 2nd phenomena: deposition of stone material on a renal papillary calcium phosphate nidus (Randall plaque). Calcium phosphate precipitates the basement membrane of the thin loops of henle and erodes and accumulates in subepithelial space of the renal papilla and breaks off.
Nephrolithiasis:
- etiology
- types of stones seen
- increased incidence seen in what part of the country?
- risk factors
- MC in what ages?
Etiology:
- low fluid intake with low volume of urine production produces high concentrations of stone forming solutes.
- hypercalcuria
Types:
- calcium
- uric acid
- cystine
- struvite
- xanthine
Increased incidence seen in the southeastern US “Stone belt”
Risks:
- family hx
- gout
- primary hyperparathyroidism
MC in 35-45YO
Nephrolithiasis:
- clinical presentation
- work up
Presentation:
- pain, hematuria
- stone in kidney usually do not cause pain, stones in the ureter do.
- acute onset severe flank pain radiating into groin
- gross/microscopic hematuria
- n/v
- fever/chills (infection)
Work up:
- UA (always look for blood and bacteria/nitrites/leukocytes
- CBC looking for elevated WBC (greater than 15000)
- CMP/BMP
- 24hr urine = MC findings: hypercalcuria, hyperoxaluria, hyperuricosuria, hypocitraturia
- KUB
- renal US (hydronephrosis; test of choice for pregnancy)
- CT scan (gold standard for stones)***
Nephrolithiasis:
-tx
depends upon stone size:
- less than 4mm 80% pass on own
- 5-7mm 50% pass on own
- greater than 8mm 0-10% pass on own
infection w/ obstructing stone = consult urologist! needs ureteral stent placement same day. Concerned for sepsis.
solitary kidney: consult urology, stent placement same day or stone removal
Pregnancy: stent placement vs pain meds
Pt preference: try to pass on own, alpha blockers (flomax, doxazozin), NSAIDS and pain meds
Surgical:
- stent placement vs percutaneous nephrostomy
- Extracorporeal shockwave (can only do this if stone is in the kidney)
- ureteroscopy
- percutaneous nephrostolithotomy
- open nephrostomy
Meds:
- flomax
- ketorolac
- hydrocodone or oxycodone
- metoclopramide
- morphine
Diet:
- increased fluids
- avoid excess salt and protein
- moderation in foods high in oxilate; green leafy vegetables, chocolates, tea
- do not limit calcium d/t hyperoxaluria
Calcium Oxalate Stones:
-made up of what?
Uric Acid stone:
-cause
Calcium Oxalate:
MC STONE! formation caused by high calcium and high oxalate excretion
Uric Acid Stone:
- low urine volume and acidic urine pH promote precipitation of uric acid
- *NOT SEEN ON XRAY!
Cystine Stones
- cause
- what do these look like?
Struvite Stones:
-caused by what?
Xanthine Stones
-cause
Cause: genetic cause
look like white pearly stones that are very hard
Struvvite Stones:
- caused by UTI of proteus or klebsiella
- can grow rapidly over weeks to months, staghorn calculus
Xanthine:
-caused by defect in xanthine oxidase
Can you dissolve stones?
NO! unless its a uric acid sstone, this is the only one that can be dissolved.
When to refer to urology:
- outpatient
- urgent inpatient
Outpatient:
- stone greater than 5mm
- failure to pass symptomatic stone after management
urgent inpatient:
- urosepsis
- intractable pain
- bilateral obstructing stones
- acute renal failure
- anuria
What is the MC stone?
What is test of choice for dx stone?
What are the two most common presentations of stones?
Calcium oxalate is MC
Test of choice is CT!
Two most common presentations are pain and hematuria!!!
Bladder Stones:
- What are they?
- MC in which gender?
- MC type of stone ?
- cause
- risk factors
- presentation
What: hard build up of minerals that form in the urinary bladder
MC in men.
MC stone is uric acid stone
cause: when urine is concentrated and materials crystalize.
Risk:
- bladder diverticulum*
- bladder outlet obstruction (MC)*
- neurogenic bladder*
- = related to BPH
- UTI
- catheters
Presentation:
- abdominal/pressure/pain
- hematuria or dark colored urine
- difficulty urinating
- urgency
- frequency
- interruption of stream
- penile discomfort
- UTI
Bladder stones
- PE findings
- dx
- tx
PE:
-rectal exam (enlarged prostate)
Dx:
bladder or pelvic xray (KUB)
-cystoscopy
-UA/UC
Tx:
- cystoscopy for small stones
- surgery:
- -cystolithalopaxy = treat through scope, use laser to break the stone up and flush out through scope.
- -cystolithotomy = make incision into bladder and pull out stones
- TURP
- Simple prostatectomy
-potassium citrate (makes urine more alkaline)
