Nephrolithiasis and Urolithiasis Flashcards
define nephrolithiasis
renal stones or calculi
Where do stones usually form?
Most commonly develop in the renal pelvis or calyces
What are stones usually composed of?
calcium oxalate or a combination of calcium and phosphate
What demographic are stones seen in?
Male > Female 3rd/4th decades, equal in 6th/7th decades
What type of stones are usually seen in middle aged males?
calcium
True/false: stones rarely occur in children
true
What is the most common type of stone composition for bladder calculi?
Most common is calcium oxalate followed by uric acid
What demographic are bladder calculi most prevalent in?
Men w/ BPH
What are predisposing factors for bladder calculi
- Dehydration
- Infection
- Change in urine pH (nl 5.8-5.9)
A. Calcium based stones in pH 5.5-6.8
B. Uric acid & Cystine stones in pH < 5.5
C. Struvite stones in pH>7.2 - Obstruction to urine flow
- Sedentary occupations
- High temp/humidity
What metabolic factors predisopse ppl to bladder stones?
Hyperparathyroidism Renal tubular acidosis Hyperuricemia Dietary -High protein/salt Renal disease
What is the pathophys of bladder stones?
- Calculi form when substances that are normally dissolved in the urine precipitate
- In appropriate conditions, stone forming substance forms crystal that becomes trapped in urinary tract
- Trapped crystal attracts other crystals to form stone
How large are bladder stones, on average?
<5mm
What are 3 common sites for ureteral stones to form?
- Ureteropelvic junction
- Crossing of ureter at iliac vessels
- Ureterovesicular junction
Where are common places for stones to occur?
Stones may form in papillae, renal tubules, calyces, renal pelvis, ureter or bladder
What type of composition of stones is most prevalent?
Calcium based stones
- Calcium oxalate
- Calcium phosphate
What pH do calcium stones form at?
pH 5.5-6.8
What is the cause of calcium based stones?
80% idiopathic
What are some risk factors for calcium based stones?
Immobilization
Hyperparathyroidism
Renal tubular acidosis
Excessive intake of Vit. D and Calcium (rare)
What comorbidity is often seen with calcium based stones?
hypercalciuria