Chapter 94: Urologic Stone Disease

Question 1

Inhibitory substance that prevent crystal precipitation and stone formation

Answer 1

Citrate and magnesium

Question 2

True or False
A diet restricting calcium paradoxically increases calcium stone formation because there is less calcium to bind oxalate in the intestinal lumen, leading to increased absorption of oxalate from the gut, recruitment of calcium from bones, osteoporosis, and symptomatic stone disease in predisposed patients

Answer 2

True
A diet restricting calcium paradoxically increases calcium stone formation because there is less calcium to bind oxalate in the intestinal lumen, leading to increased absorption of oxalate from the gut, recruitment of calcium from bones, osteoporosis, and symptomatic stone disease in predisposed patients

Question 3

Kidney stone most commonly seen in women with UTI

Answer 3

Struvite (magneisium-ammonium-phosphate)

Question 4

True or False
Antibiotic penetration into staghorn calculi is poor, and the potential for urosepsis exists as long as the stones remain

Answer 4

True
Antibiotic penetration into staghorn calculi is poor, and the potential for urosepsis exists as long as the stones remain

Question 5

Drug for HIV that causes renal stone

Answer 5

Protease inhibitor Indinavir sulfate

Question 6

True or False
During acute obstruction, most patients have no rise in serum creatinine because the unobstructed kidney functions at up to 185% of its baseline capacity

Answer 6

True
During acute obstruction, most patients have no rise in serum creatinine because the unobstructed kidney functions at up to 185% of its baseline capacity

Question 7

The most common site of obstruction of kidney stone

Answer 7

• Uretero- pelvic junction, where the 1-cm pelvis constricts into the 2- to 3-mm ureter
• The pelvic brim, where the ureter courses over both the pelvis and the iliac vessels
• Ureterovesical junction

Question 8

The most constricted site of the ureter?

Answer 8

Ureterovesical junction because this is the most constricted site of the ureter due to the muscular coat of the bladder

Question 9

True or False

Stone size on plain radiographs is magnified by up to 20%, and a measured stone on CT is 88% of actual stone size

Answer 9

True

Stone size on plain radiographs is magnified by up to 20%, and a measured stone on CT is 88% of actual stone size

Question 10

The classic symptoms of complex nephrolithiasis

Answer 10

The classic symptom complex for nephrolithiasis is the acute onset of a crampy intermittent flank pain that radiates toward the groin

Question 11

How many percent of patient with renal colic will present hematuria?

Answer 11

Hematuria is present in only 85% of patients with renal colic, and 30% have gross hematuria

Question 12

The risk factors for a poor outcome with renal stones include three categories

Answer 12

• Renal function at risk
• History of difficulty with stones
• Infection

Question 13

Mimicker of renal stone that should be excluded

Answer 13

• Abdominal aortic aneurysm

- Renal artery infarction

Question 14

The most common misdiagnosis given to patients with a rupturing or expanding abdominal aortic aneurysm

Answer 14

Nephrolithiasis

Question 15

How many percent of patient with flank pain and hematuria have no radiographic evidence of ureterolithiasis

Answer 15

24% of patients with flank pain and hematuria have no radiographic evidence of ureterolithiasis

Question 16

In non contrast CT scan. What sign will you see in ureteral obstruction

Answer 16

• Ureteral dilatation
• Stranding of perinephric fat
• Dilatation of the collecting system
• Renal enlargement

Question 17

True or False

Low-dose CT is as sensitive as standard CT in detecting stones >3 mm in patients with a body mass index <30 kg/m2

Answer 17

True

Low-dose CT is as sensitive as standard CT in detecting stones >3 mm in patients with a body mass index <30 kg/m2

Question 18

The first-line imaging modality in pregnant patients with kidney stone

Answer 18

Ultrasound

Question 19

True or False

US may miss smaller (<3 mm in diameter) ureteral stones

Answer 19

False

US may miss smaller (<5 mm in diameter) ureteral stones

Question 20

True or False

US is helpful in diagnosing stones in the proximal and distal ureters but is insensitive for mid-ureteral stones

Answer 20

True

US is helpful in diagnosing stones in the proximal and distal ureters but is insensitive for mid-ureteral stones

Question 21

Best diagnostic accuracy in kidney stone was found with ____

Answer 21

Noncontrast CT scan

Question 22

Drug use in kidney stone that has direct action on the ureter by inhibiting prostaglandin synthesis

Answer 22

NSAIDs (Ketorolac 10 - 30mg IV)

Question 23

Drug use in kidney stone that reduce smooth muscle tone and reduce transmission by afferent sensory pathways

Answer 23

Lidocaine 1.5mg/kg IV

Question 24

True or False

IV lidocaine may provide pain relief sooner than IV morphine

Answer 24

True

IV lidocaine may provide pain relief sooner than IV morphine

Question 25

What drug you can give in patient with kidney stone and UTI without signs of renal compromise like renal insufficiency or systemic signs of infection

Answer 25

• Gentamicin or tobramycin, 3.0 milligrams/kg/d divided every 8 hours, plus ampicillin, 1 to 2 grams every 4 hours

Question 26

The most commonly used drug for medical expulsion therapy

Answer 26

Tamsulosin 0.4mg PO OD an alpha blocker

Question 27

True or False
Average time for stone passage varies according to size and location but may range up to 7 to 30 days for stones 5 to 6 mm in diameter

Answer 27

True
Average time for stone passage varies according to size and location but may range up to 7 to 30 days for stones 5 to 6 mm in diameter

Question 28

At what stage of pregnancy most commonly kidney stone seen?

Answer 28

2nd to 3rd trimester

Question 29

True or False
The radiation doses for various imaging modalities for stones are as follows:
kidney-ureter-bladder, 0.05 to 0.15 cGy
three-film IV pyelogram, 0.15 to 0.20 cGy
CT scan, 2.2 to 2.5 cGy

Answer 29

True
The radiation doses for various imaging modalities for stones are as follows:
kidney-ureter-bladder, 0.05 to 0.15 cGy
three-film IV pyelogram, 0.15 to 0.20 cGy
CT scan, 2.2 to 2.5 cGy

Question 30

Pain medication use in pregnant with kidney stone

Answer 30

NSAIDS are not recommended, so narcotic pain control is most commonly used

Question 31

Drug that known to be safe in pregnancy, has been recommended for medical expulsive therapy in pregnant patients

Answer 31

Nifedipine