Stone formation/ urolithiasis Flashcards
(35 cards)
Name 6 different ethiologies for stone formation:
Deranged calcium metabolism Cystine uria Uric acid stones (urinsyra) Infection stones Genetic Drugs
Name 5 ways calcium metabolism can be deranged:
Hypercalciuria
Hyperoxaluria
Hypocitraturia
Hyperuricosuria
Hypermagnesuria
How will Hypocitraturia cause stones?
Low citrate: Powerful inhibitor of cristallization
Low pH: consumes citrate
Extra:
Thiazid induced Hypocitraturia:
Thiazid –>intracellular acidosis –>acidosis inhibits citrate synthesis –> increased cellular absorbtion of citrate –> low citrate in the urine
What drug can cause Hypocitraturia and by what mechanism?
Thiazid induced Hypocitraturia:
Thiazid –>intracellular acidosis –>acidosis inhibits citrate synthesis –> increased cellular absorbtion of citrate –> low citrate in the urine
What type of stones will hypocitraturia cause?
calcium oxalate
calcium phosphate
What dietary supplement is full of citrate?
Orange juice
What are the causes of Calcium oxalate stones?
Hypercalciuria
Hyperoxaluria
Hypocitraturia
Hyperuricosuria
Hypermagnesuria
What are the causes of Calcium phosphate stones?
Hypercalciuria
Hypocitraturia
Hyperuricosuria,
what is the cause?
high uric acid in the blood
excess of purine intake:
most often cause by gout
but also by systemic disease such as
type 2, metabolic syndrome proliferative syndrome, drugs etc.
or/and
low pH
caused by for example
insulineresistance, metabolic syndrome, diarreah
Treatment for hyperuricosuria?
Allopurinol
Treatment for hypocitraturia:
Correct hypokalemia and pH
give
potassium chloride or
potassium citrat (kaliumcitrat)
Causes of hyperoxaluria:
Low diuresis
High oxalate intake
Low calciumintake
Treatment for hyperoxaluria:
Increase fluids Limit oxalate (chocolate, spinach, nuts etc) Limit fat Increase calcium Vitamin B6 Correction of bowel pathology
Thiazides effect on stone formation:
Thiazid induced Hypocitraturia:
Thiazid –>intracellular acidosis –>acidosis inhibits citrate synthesis –> increased cellular absorbtion of citrate –> low citrate in the urine
Thiazides can increase calciumreabsorbtion and be used for the treatment of hypercalciuria
Causes of hypercalciuria:
Low diuresis
High calcium intake
High protein intake
High salt intake
Metabolism: hyperparathyreoidism
Treatment for hypercalciuria:
Increase fluids
Limit calcium
Limit protein
Limit fat
Thiazides:
increases calciumreabsorbtion
What is the effect of animal protein on stone formation?
more uric acid due to purine load
low urine pH due to acid load (hypocitraturia)
high calcium due to low pH
What are the causes of Cystine uria?
Low diuresis High protein intake High salt intake High intake of methionine food (Parmesan, egg, horsemeat etc.) Low pH
Treatment of Cystine uria:
Increase fluids Limit protein Limit fat Limit salt Limit methionine
Tiopronine Potassium citrate (kalium citrat)
Name 4 infection stones:
Hydroxy apatite
Carbonate apatite
Struvite (Magnesium ammonium phosphate)
Ammonium urate
Treatment of infection stones:
Remove stone and treat UTI
Vilka stenar passar för ESWL-behandling?
sten ≤ 2 cm
i njurbäckenet
i övre och mellan kalkar
går även för uretärstenar men är mindre effektivt
När kan man genomföra “akut” ESWL?
singelsten i PUJ < 1,5 cm avflödeshinder inom 24-48 H inget ödem eller "impacted" sten dilatation pga obstruktionen
Hur vanligt är det med njurstensanfall efter ESWL?
2-4%
