Nephrolithiasis

Question 1

kidney stones are most common in what demographic?

Answer 1

older white men

Question 2

what type of stone is caused by UTIs?

Answer 2

struvite

Question 3

what are the 6 factors that cause kidney stones?

Answer 3

1. decreased urine volume, increased urinary concentration
2. excessive excretion of stone forming substances
3. anatomic abnormalities
4. urine pH - alkaline or acid
5. presence or absence of urinary inhibitors (citrate, Mg, pyrophosphate, trace metals)
6. urinary potentiators (crystal nidus)

Question 4

what is the main type of kidney stone?

Answer 4

calcium oxalate

Question 5

what is the appearance of struvite (magnesium ammonium phosphate) crystals?

Answer 5

coffin lid

Question 6

what are the radiolucent stones?

Answer 6

• uric acid

- cysteine

Question 7

what is the best diagnostic test to use for kidney stones?

Answer 7

helical CT

Question 8

what type of environment is conducive for calcium stones?

• volume
• pH
• calcium status
• oxalate status
• citrate status
• uric acid status)

Answer 8

• low urine volume
• high pH
• hypercalciuria
• hyperoxaluria
• HYPOcitraturia
• hyperuricosuria

Question 9

how do dietary sodium and protein intake affect urinary calcium?

Answer 9

increase

Question 10

what is the inheritance of Dent disease?

Answer 10

x linked

Question 11

what part of the nephron is affected in dent disease? what are the manifestations?

Answer 11

• proximal tubule
• hypercalciuria
• nephrocalcinosis
• nephrolithiasis
• kidney failure in 5th decade

Question 12

what type of diuretics are used to treat calcium stones? why?

Answer 12

• thiazide

- reduces sodium presence, reducing calcium excretion due to mild volume depletion

Question 13

what are the treatments for calcium oxalate stones?

Answer 13

• fluid
• diet
• thiazides
• potassium citrate
• bisphosphonates

Question 14

fat malabsorption can lead to what type of stone? what is the pathogenesis?

Answer 14

• hyperoxaluria - calcium oxalate stones

- fat binds calcium, leaves oxalate free to form stones

Question 15

what is the pathogenesis of medullary sponge kidney?

Answer 15

• dilatation of collecting ducts
• stasis
• calcium stones

Question 16

are stone formers more or less likely to have HTN?

Answer 16

more likely

Question 17

struvite stones are associated with what pathogen? what class in general?

Answer 17

• proteus

- urease positive organisms

Question 18

what is a diagnostic clue for struvite stones?

Answer 18

alkaline urine pH

Question 19

lesch-nyhan and kelly seegmiller diseases are associated with what type of kidney stones? these diseases are characterized by a lack of what enzyme?

Answer 19

• uric acid stones

- HPRT deficiency

Question 20

what are the causes of uric acid stones?

Answer 20

• gout
• hyperuricemia
• hyperuricosuria
• chronic diarrhea
• acidic urine pH
• low urine volume

Question 21

what type of urine pH causes uric acid stones?

Answer 21

acidic

Question 22

what is the therapy for uric acid stones?

Answer 22

• alkalinize urine

- allopurinol

Question 23

cystine stones form from a disorder causing lack of reabsorption of what amino acids?

Answer 23

• cysteine
• ornithine
• arginine
• lysine

Question 24

what medications make cysteine more soluble, preventing cystine stones?

Answer 24

• penicillamine
• captopril
• mercaptoproprionylglycine