Clinical III: Nephrothiasis Flashcards
What are some things to keep in mind when evaluating a patient with hematuria?
- gross vs microscopic (invisible to eye; >2 RBCs/field)
- pain (UTI) vs painless (cancer)
- glo (dysmorphic RBCs) vs non-glo (Upper or Lower tract)
- age: > 50 increased risk of cancer
What is the biggest risk factor for causing urologic cancer?
- tobacco smoking!
- toxins are filtered by kidney and end up in the bladder and becoming more concentrated
How do we test to rule out cancer?
upper tract:
- CT w/ contrast
- renal ultrasound
lower tract:
- cystoscopy
- cytologic studies of urine: urine analyzed in lab
Next steps after: microscopic blood + asymptomatic + no risk factors for uro cancers?
redo sample to check
if negative = no further testing required
if positive for 2nd time = follow up!
Next steps after: microscopic blood + asymptomatic + no risk factors for uro cancers + positive microscopy 2nd time
classify into—-
*glo: RBC casts/dysmorphic RBCs > inc. renal indices + proteinuria = refer to nephrologist
*non-glo: no RBCs or casts; no proteinuria or renal findings = image upper tract first > then lower tract (if necessary)
—upper tract positive for mass or polycystic disease = refer to urology
—-if negative (-): further workup depends on risk factors; if > 40 yo: do lower tract imagining
How to manage gross hematuria?
-catheterization + bladder irrigation with saline wash: rinse out urokinase to prevent bleeding
What are the clinical findings associated with nephrolithiasis?
- upper tract: flank pain
- lower tract: groin or labial pain
- hematuria
How do stones form?
-super saturated solution in the bladder [via excess solute] + nucleation phase (caused by uric acid crystals)
What are the four types of stones?
Calcium*
Uric acid
Struvite
Cysteine
*most common
Treatment of active stone?
Medical intervention:
- pain control
- IV fluids
- tamsolin/alpha adrergic blocker: relaxes ureters
- diuretic
- acidifiy or alkanalize urine
Surgical intervention required for:
- stubborn stones
- extreme pain
- infection + stones = abscess
What things promote stone formation?
- excess Na
- low urine pH
- prior injury
- oxalate
What things inhibit stone formation?
- citrate
- high urine flow rate
Calcium stones: how are they formed? What diseases are they associated with?
caused by:
- hypercalcuria
- increased oxalate
- Crohn’s: malabsorption of fatty acids and bile salts that keep Ca around
- antifreeze ingestion*
- low pH: calcium oxalate
- high pH: calcium phosphate
How does excess oxalate cause stones?
- In GI: ca + oxalate = insoluble = poop out
- Renal + excess oxalate: Ca + oxalate = precipitates out into urine = stone formation
Uric stones: how are they formed? What diseases are they associated with?
- chronic metab acidosis
- hyperuricosuria
- metabolic syndrome: insulin resistance = decrease ammonia production = low urine pH
