Nephrolithiasis

Question 1

Most common type of kidney stone

Answer 1

Calcium oxalate (~15%)

Question 2

Conditions that predispose to stone formation

Answer 2

-GI malabsorption (Chron’s disease, gastric bypass surgery)
-Primary hyperparathyroidism
-Obesity
-Type 2 DM
-Distal renal tubular acidosis

Question 3

Most clinically important inhibitor of calcium-containing stones

Answer 3

Urine citrate

Question 4

Types of kidney stones

Answer 4

Calcium oxalate (~75%)
Calcium phosphate (~15%)
Uric acid (~8%)
Struvite (~1%)
Cystine (<1%)

Question 5

Dietary factors that are associated with increased risk of nephrolithiasis

Answer 5

Animal protein
oxalate
sodium
sucrose
fructose

Question 6

Dietary factors associated with a lower risk

Answer 6

Calcium
Potassium
Phytate

Question 7

Vitamin that causes calcium oxalate stone formation in men

Answer 7

Vitamin C supplements

Question 8

urine pH that is favorable for formation of urine acid stone

Answer 8

<=5.5

Question 9

urine pH that is favorable for formation of calcium phosphate stones

Answer 9

> =pH 6.5

Question 10

Two common presentations for individual with acute stone event

Answer 10

Renal colic
Painless gross hematuria

Question 11

Stone that is visualized in helical computed tomography

Answer 11

Uric acid stones (“radioluscent”)

Question 12

Answer 12

Calcium oxalate stones

Question 13

Answer 13

Cystine stones

Question 14

Role of hydration in management of nephrolithiasis

Answer 14

Excessive fluid administration has not been shown to be beneficial.
The goal should be to maintain euvolemia

Question 15

Potential benefit of alpha blocker therapy

Answer 15

May increase the rate of spontaneous stone passage

Question 16

Indications of urologic intervention

Answer 16

-Evidence UTI (“pus under pressure”)
-Low probability of spontaneous stone passage (stone measuring >= 6 mm or an anatomic abnormality)
-Intractable pain

Question 17

Finding in the urinalysis that is a strong risk factor for new stone formation

Answer 17

Crystalluria

Question 18

The gold standard diagnostic test for nephrolithiasis

Answer 18

Helical CT without contrast

Question 19

Goal urine volume to reduce the likelihood of crystal formation

Answer 19

2L/d

Question 20

Risk factors for calcium oxalate stone

Answer 20

Higher urine calcium
Higher urine oxalate
Lower urine citrate

Question 21

The only known strategy that reduces endogenous oxalate production

Answer 21

Avoiding high-dose vitamin C supplementation

Question 22

Foods that contain high amounts of oxalate

Answer 22

Spinach
Rhubarb
Almonds
Potatoes

Question 23

Two main risk factors for uric acid stones

Answer 23

1. Persistently low urine pH
2. Higher uric acid excretion

Question 24

Mainstay of prevention of uric acid stone formation

Answer 24

Increasing urine pH

Question 25

Treatment of choice for urine cystine excretion

Answer 25

Tiopronin

Question 26

Preferred alkalinizing agent to achieve a urine pH of 7.5 in cystinuria

Answer 26

Potassium citrate or bicarbonate

Question 27

Form only when the upper urinary tract is infected with urease-producing bacteria such as Proteus mirabilis, Klebsiella pneumoniae, or Providencia sp

Answer 27

Struvite stones (Infection stones, Triple-phosphate stones)