Nephrolithiasis

Question 1

What is the most important factor to correct with kidney stones?

Answer 1

low urinary flow

Question 2

What might explain the higher incidence of kidney stones in men?

Answer 2

Women typically excrete more citrate and less calcium than men

Question 3

Why is the southeastern United States considered the Stonebelt?

Answer 3

Wide consumption of iced tea. Tea is loaded with calcium oxalate.

Question 4

How might excess dietary sodium contribute to kidney stones?

Answer 4

leads to excessive Ca and uric acid urine secretion

Question 5

How might renal tubular acidosis contribute to kidney stones?

Answer 5

decreased Ca reabsorption

Question 6

How might excess dieatary meat contribute to kidney stones?

Answer 6

uric acid overproduction

Question 7

What is the most common stone composition?

Answer 7

Calcium oxalate 80%

Question 8

What conditions are calcium phosphate stones associated with?

Answer 8

renal tubular acidosis & Primary Parathyroidism

Question 9

What do calcium phosphate crystals look like under microscope?

Answer 9

long crystalline rods

Question 10

What do uric acid crystals look like under microscope?

Answer 10

irregular-shaped crystals

Question 11

Clinical presentation of stones

Answer 11

pain, hematuria, N/V, dysuria, urgency

Question 12

Most common places a stone will cause obstruction

Answer 12

Ureter at the abdominal crease and ureterovesicular junction

Question 13

Characterization of pain associated with kidney stone

Answer 13

severe intermittent colicky flank pain. Localized to the CVA

Question 14

Characterization of pain associated with ureteral stone

Answer 14

sharp, acute, spasm-like flank pain. Movement down will radiate pain to umbilical region, then to groin

Question 15

Gold standard for diagnosing nephrolithiasis

Answer 15

Non-contrasted helical CT scan

Question 16

What is the imaging test of choice during pregnancy for a suspected stone?

Answer 16

ultrasound.

Question 17

What labs do you need to check before prescribing Toradol or other NSAID?

Answer 17

BMP to check Cr

Question 18

If a stone is <5mm what percent pass spontaneously?

Answer 18

90%

Question 19

For a stone 5-10mm what can increase the chance of passage?

Answer 19

alpha & calcium channel blockers (dilate ureters so stone can pass)

Question 20

Name 4 alpha 1 blockers

Answer 20

doxazosin (Cardura), prazosin (Minipress), Terazosin, Tamsulosin (Flomax)

Question 21

Most important factor for acute treatmant and to prevent stone recurrence

Answer 21

increase urine output to 2 L/day by increased fluids

Question 22

Relapse rate in the first 5-10 yrs after first episode

Answer 22

50%

Question 23

treatment for hypercalciuria calcium oxalate stones

Answer 23

thiazide diuretics, decreased Na intake

Question 24

treatment for hyperoxaluria stones

Answer 24

decrease oxalate intake, increase Ca intake (binds enteric oxalate)

Question 25

treatment for hypocitraturia stones

Answer 25

potassium citrate

Question 26

treatment for uric acid stones

Answer 26

allopurinol and potassium citrate

Question 27

how does citrate prevent stones?

Answer 27

inhibits calcium salt formation

Question 28

What is the composition of struvite stones?

Answer 28

magnesium, ammonium, and calcium phosphate

Question 29

What is the most common UTI urea-splitting organism that can contribute to struvite stones?

Answer 29

proteus

Question 30

What causes cystine stones?

Answer 30

Autosomal recessive disorder leading to decreased cystine resorption in the kidney- acidic urine

Question 31

treatment for cystine stones

Answer 31

Hydration, urine alkalization, Low Na/protein diet cystine binders

Question 32

What drugs promote calcium stone formation?

Answer 32

loops, antacids, glucocorticoids, theophylline, Vitamins D & C

Question 33

What drugs precipitate into stones?

Answer 33

acyclovir, indinavir, triamterene

Question 34

Most common surgical treatment for stones

Answer 34

shock wave lithotripsy