Nephrolithiasis Flashcards
Most often, stones form in … and move to…
Most often, stones form in the kidney (kidney stones) and move down to the ureter (ureteral stones).
When do stones cause pain?
When they block flow of urine (usually when they move down to the ureters).
What are kidney stones most often made of?
calcium oxalate
What is the difference between kidney stones and gallstones?
Gallstones are made of CHOLESTEROL, not calcium.?
Why do people have stones? (6)
- Poor fluid intake/hot weather
- Hereditary
- Recurrent UTIs
- Medications
- Immobility
- Genetic/metabolic diseases (rare)
What type of medications can cause stones?
Indinavir
Triameterene
Describe the pain caused by stones
Acute, colicky flank pain radiating to the groin.
CVA tenderness.
Summarize the clinical presentation of stones.
When you suspect a kidney stone, what investigations should be made?
- Urinalysis
- Low-dose (no contrast) CT scan (gold standard)
- KUB x-ray
- Ultrasound (in pregnant women)
What do we look for in a urine sample (microscopic examination) when investigating stones?
- blood
- crystals
- bacteria
When does a stone require urology consultation for emergent decompression (when is it an emergency)?
- Obstructing ureteral stone with infection (most important)
- Impending renal deterioration/failure
- Pain refractory to analgesics
- Intractable nausea/vomiting
- Patient preference (multiple ER visits)
Which hurts more and why?
Small stones…?
How do we manage stones when emergent decompression is not indicated?
Most small stones (<5mm) pass spontaneously.
Treatment:
- Lots of water and painkillers
- Lasts 3-6 weeks
- NSAIDs
How does stone size affect passage rates?
The larger the stone, the longer they will take to pass.
Stones of >5mm will usually require surgery (otherwise the patient may risk losing their kidney).
To remove kidney stones, we have 3 minimally-invasive surgery options…
- Shock-wave lithotripsy
- Ureteroscopy
- Percutaneous nephrolithotomy
