Calculus Disease Flashcards
Do men or women tend to get calculus disease (kidney stones) more often?
- MEN
What are some risk factors for calculus disease (nephrolithiasis; kidney stones)?
- family hx (genetics)
- increased weight
- previous stone
- diet (salt)
- climate (warm)
- gender (male)
- water supply (calcium, magnesium)
- occupation/stress
What diet components contribute to nephrolithiasis?
- oxalate (binds to calcium and precipitates out)
- animal proteins (nitrogen contributing to uric acid stones)
- animal fat
- vitamin D
- fish oils
- vitamin C (converted to oxalate)
- calcium (binds to oxalate and precipitates out)
- phosphorus (phosphorous stones).
What is the most common type of stone?
- CALCIUM OXALATE MONOhydrate= hard
- CALCIUM OXALATE DIhydrate= less hard.
What is important to know about calcium PHOSPHATE stones?
- less common and often contain calcium oxalate.
- may be associated with hyperparathyroidism and renal tubular acidosis.
What are the effects of animal protein from the diet on nephrolithiasis?
- increased calcium
- increased sulfate
- increased uric acid
- decreased pH (can’t form stones above 5.5).
- decreased citrate (citrate such as from orange juice or lemonade actually helps to prevent stones).
What is associated with URIC ACID STONES?
- GOUT
* more people will form uric acid stones before gout, bc the kidneys are good at excreting serum uric acid.
What causes uric acid stones?
- uric acid is the end product of purine metabolism.
- increased dietary purine intake
- uricosuric drugs (allopurinol), which impair uric acid reabsorption from proximal tubule.
- obesity and alcohol
- myelo- and lymphoproliferative diseases
- inborn metabolic disorders
- chronic diarrheal syndromes
What are some clinical characteristics of uric acid stones?
- renal colic
- hematuria
- low urinary pH (less than 5.5)
- NEGATIVE plain x-rays (radiolucent)
- CT or US confirmation
What are STRUVITE CALCULI? (staghorn)
- referred to as “infection,” “urease,” and “triple phosphate stones”
- composed of magnesium ammonium phosphate and carbonate apatite.
- more FEMALES than males bc women get UTIs more than men.
- most prevalent form in those with supravesical diversions and neurogenic bladders.
What is essentially a prerequisite for struvite calculi?
- urinary infection with urease-synthesizing organism.
Are bacteria contained within the interstices of struvite calculi?
- YES and are protected from antibiotic therapy (aka antibiotics won’t work).
What is the urine pH for struvite calculi?
- greater than 7.5
What are the most common bacteria in struvite calculi (urease producers)?
- proteus vulgaris
- proteus mirabilis
- you will NEVER see E. coli bc it does NOT produce urease.
What are the clinical manifestations of struvite calculi?
- often asymptomatic bc the stones are so large to fit in the ureters.
- often associated with indwelling catheters.