12.6 Nephrolithiasis Flashcards
risk factors of nephrolithiasis
- high concentratin of solute in urine
- low urine volume
nephrolithiasis:
clinical presentation, classic (3 symptoms)
- Colicky pain–sharp, localized, spasmic
- hematuria
- unilateral flank tenderness
nephrolithiasis
- how long typically to pass the stone?
- what if not passed during that time?
- within hours
- if not passed, surgical intervention may be required
List types of kidney stones (4)
-most common to least common
- Ca oxalate, Ca phosphate. (usu in adults)
- ammonium magnesium phosphate (AMP) (aka Struvite stones or ‘infection stones’)
- Uric acid (gout)
- Cystine (rare, seen in children)
Ca oxalate/ Ca phosphate stones:
- causes (3)
- most common?
- idiopathic hypercalciuria (blood [Ca] is normal!)
- hypercalcemia (rule this out)
- Crohn’s disease–small bowel damage allows more oxalate to be absorbed, which binds Ca in the blood.
Crohn’s disease and kidney pathology:
relation?
May get Ca oxalate stones.
small bowel damage leads to increase absorption of oxalate, which binds Ca in the blood.
Ca oxalate/ Ca phosphate stones:
Tx, why?
- HCTZ
- Ca sparing diuretic, so less Ca in urine
Ammonium magnesium phosphate (AMP) stone:
-most common cause
- infection with urease-positive organisms (eg Proteus vulgaris, Klebsiella)
- Urease breaks down urea into CO2 and ammonia, which is basic. alkalinization of urine leads to stone formation
Ammonium magnesium phosphate (AMP) stone:
- classic presentation
- tx
- staghorn calculi in the renal calyces. UTI can form there.
- Too big to pass, requires surgery
- also tx underlying infection to prevent recurrence
Urate stone
-causes/risk factors
Risk factors:
- Gout
- hyperuricemia (leukemia, myeloproliferative disorders)
- hot, arid climates, low urine volume
- acidic pH
What kidney stone is radiolucent?
Urate stones
-all others can be seen in x ray
Urate stones
-tx
- Hydration
- alkalinzation of urine (b/c acidic urine causes stone)
- use Potassium Bicarbonate to increase pH - Allopurinol– decrease urate production for pts with gout
what disorders increase risk of urate stone formation?
(2)
- Gout
- leukemia and myeloproliferative disorders (increased cell generation and turnover of nuclear material means more urate formation in purine pathway)
Staghorn calculus, think what?
in a child, think what?
- think AMP stone
- in child, think Cystine stone
Cystine stone
-what assoc with
-assoc with cystinuria (genetic defect of tubules, results in decreased reabsorption of cysteine)
