Intern Year: Tintinalli- Section 10-Ch 97 Urologic Stone Dz

Front 1

most common stone?

most common cause of staghorn calculi (forms a cast in the renal pelvis)?

Back 1

most common stone: Calcium

most common cause of staghorn calculi (forms a cast in the renal pelvis): Struvite -- aka magnesium-ammonium-phosphate

Front 2

in a patient with an acute obstruction due to nephrolithiasis, what would you expect the creatinine to be like?

Back 2

it actually stays the same

this is because the unobstructed kidney functions at up to 185% of its baseline capacity

if it does elevate this suggests a solitary kidney or disease in the other kidney that will not allow it to compensate adequately

Front 3

3 most common sites of stone obstruction?

Back 3

Ureteropelvic junction (UPJ): 1cm pelvis constricts into the 2 to 3 mm ureter

Pelvic Brim: where the ureter courses over both the pelvis and the iliac vessels

Ureterovesical junction (UVJ): this is the most constricted site of the ureter due to the muscular coat of the bladder

Front 4

98% of what sized stones will pass within 4 weeks without intervention?

Back 4

<5mm

note: sixty percent of stones 5-7mm and 39% of stones >7mm will pass within 4 weeks

Front 5

How does ACTUAL STONE SIZE compare to the size seen on Xray?

on CT?

Back 5

Xray: 20% MAGNIFICATION

CT: 88% of actual size (so its bigger in actuality)

Front 6

Hematuria is present in approximately what percentage of pts with renal colic?

Back 6

85%

note: only 30% have gross hematuria

Front 7

Nephrolithiasis is the most common misdiagnosis given to patients who actually have ______?

Back 7

rupturing or expanding AAA

oops...

remember stones do not typically present in pts >60 y.o. and do not cause hypotension even transiently

Front 8

what defines Hematuria?

Back 8

5 or more RBCs per high power field

Front 9

What percent of patients with flank pain and hematuria have no radiographic evidence of ureterolithiasis?

Back 9

24%

Front 10

primary choice of analgesic in the tx of stone dz?

Back 10

NSAID

have direct action on the ureter by inhibiting prostaglandin synthesis

think ketorolac

Front 11

what anti-emetic drug is indicated in stones?

Back 11

Metoclopramide

dopaminergic receptor blocker in CNS

also provides pain relief

Front 12

what class of medication is associated with increased rate of expulsion of a stone, decreased time to expulsion, and decreased pain?

Back 12

alpha blockers (tamsulosin)

number needed to treat is 3.3

2-6 day improvement in expulsion time

Front 13

average time to pass a stone 5-6mm in diameter?

Back 13

7-20 days

id rather die.

Front 14

Patients with hematuria, negative imaging studies and no other source require what?

Back 14

outpatient urologic follow up to figure out the cause

Front 15

Absolute indications for admission with a stone?

Back 15

Intractable pain/vomiting

urosepsis

single or transplanted kidney with obstruction

ARF

hypercalcemic crisis

severe medical comorbitities

Front 16

What is a common US finding in pregnant women when looking for a stone?

Back 16

Physiologic hydronephrosis

more common/severe on the right

Front 17

Fetal malformation rate is increased by 5% at 10 cGy when a mom is radiated...

that being said, what is the amount of radiation received when a pt gets a...

KUB:

3 film IV pyelogram:

CT:

Back 17

KUB: 0.05-0.15

3 film IV pyelogram: 0.15-0.20

CT: 2.2-2.5