Stone Formation and Urolithiasis

Question 1

T/F. Stone formation is multifactorial

Answer 1

True (e.g. genetic, diet, physical environment, stress)

Question 2

T/F. Rate of stone formation is not proportional to % of large crystals and crystal aggregates.

Answer 2

False (proportional)

Question 3

Determines stone production

Answer 3

Saturation of each salt and the concentrations of inhibitors and promoters

Question 4

3 anatomic ureteral constrictions

Answer 4

[1] Ureteropelvic junction, [2] crossing of ureter at level of iliac vessels, [3] ureterovesical junction

Question 5

5 surgical constrictions of the ureter

Answer 5

3 anatomic constrictions + [4] ureter crossing vas deferens/broad ligament, [5] ureteral meatus

Question 6

T/F. Stone <4 mm can’t pass through GUT

Answer 6

False (readily pass)

Question 7

T/F. Nephrocalcinosis is a medical emergency

Answer 7

False (do not have potential for obstruction)

Question 8

Central event in stone formation

Answer 8

Supersaturation

Question 9

Most important urinary ion

Answer 9

Calcium

Question 10

Amount of Ca reabsorption

Answer 10

<2 % excreted in urine (the rest is reabsorbed)

Question 11

T/F. Increase in monosodium urates and a decrease in urinary pH further interfere with Ca complexation and therefore promote crystal aggregation

Answer 11

True

Question 12

T/F. Ca affects amount of oxalate absorption in small bowel

Answer 12

True

Question 13

T/F. Uric acid is a product of pyrimidine metabolism

Answer 13

False (purine metabolism)

Question 14

T/F. Na directly affects Ca stone formation

Answer 14

False (indirectly as it regulates Ca metabolism)

Question 15

Most active inhibitory component of urine

Answer 15

Citrate

Question 16

Inhibitor which is a component of struvite calculi

Answer 16

Magnesium

Question 17

T/F. Sulfate is not a stone formation inhibitor

Answer 17

False

Question 18

Pathogenesis of calcium stones

Answer 18

↑ urinary calcium
↑ urinary oxalate
↓ level of urinary citrate

Question 19

Tx for type I absorptive hypercalciuria

Answer 19

Cellulose phosphate

Question 20

Most common absorptive hypercalciuria

Answer 20

Type II

Question 21

Tx for Type II absorptive hypercalciuria

Answer 21

Dietary calcium restriction to 400 to 600 mg/day

Question 22

Tx for type III absorptive hypercalciuria

Answer 22

Orthophosphate

Question 23

Hypercalciuria 2⁰ to Primary hyperparathyroidism (most commonly due to adenoma)

Answer 23

Resorptive Hypercalciuric Nephrolithiasis

Question 24

Infection stone 2⁰ to urea splitting organisms e.g. Proteus, Pseudomonas and assoc. with staghorn calculi

Answer 24

Struvite

Question 25

Composition of struvite

Answer 25

Mg, Ammonium (gives alkaline pH), Phosphate

Question 26

T/F. Uric acid stone more common in women

Answer 26

False (men)

Question 27

Struvite vs uric acid stones

Answer 27

Struvite: dissolve in acid just like xanthine | Uric acid: dissolve in alkaline

Question 28

Tx if serum uric acid is high

Answer 28

Allopurinol

Question 29

Stone due to inborn error of metabolism i.e. intestinal absorption of dibasic amino acid

Answer 29

Cystine

Question 30

Signs and symptoms of stone

Answer 30

Pain (renal colic), hematuria, fever, nausea and vomiting

Question 31

Common nerve pathway of kidney and stomach

Answer 31

Celiac ganglion

Question 32

Classic signs of appendicitis

Answer 32

Dull pain navel area that progresses to sharp pain in LRQ; loss of appetite; abdominal pain after nausea and vomiting; abdominal swelling; fever; inability to pass gas

Question 33

Radiation of pain in proximal ureter stone

Answer 33

Radiates to the groin and testicle in male, labia majora and round ligament in female

Question 34

Simplest, minimally invasive, cheapest imaging

Answer 34

UTZ

Question 35

Next line imaging if negative in initial imaging

Answer 35

Retrograde pyelography

Question 36

Series of x-rays (plain KUB)

Answer 36

Scout films

Question 37

Contraindication for IV pyelography

Answer 37

↑ serum creatinine; dye is nephrotoxic

Question 38

Uric acid and xanthine stone on pyelography

Answer 38

Radiolucent

Question 39

Calcium oxalate and calcium phosphate stones on pyelography

Answer 39

Radio opaque

Question 40

Obliterated psoas line on imaging might mean

Answer 40

Mass in retroperitoneal area

Question 41

May be performed to delineate the entire ureter to check for stones, masses, or strictures using dynamic fluoroscopy

Answer 41

Retrograde pyelography

Question 42

Stones on CT

Answer 42

Hyperintense regardless of nature

Question 43

Benefits of stent

Answer 43

Allows medication to come in contact with stone or else all meds will to the contralateral kidney

Question 44

Management of obstructed and infected kidney and fever

Answer 44

Emergency drainage

Question 45

Ureterolithic agents to relax ureter and reduce peristalsis

Answer 45

Hyoscine butylbromide (buscopan) and alpha adrenergic blockers

Question 46

Agents for acidification of struvite stone

Answer 46

Suby’s G solution and hemiacidrin

Question 47

Effect of orange juice on urine

Answer 47

Alkalinize

Question 48

Oral alkalinizing agents

Answer 48

Na or K bicarbonate and K citrate

Question 49

Pain relievers for colic pain

Answer 49

IM 50-100 mg meperidine or 10-15 mg morphine, NSAIDs

Question 50

Chance of spontaneous passing of 4-5 mm stone

Answer 50

40-50%

Question 51

Chance of spontaneous passing of >6 mm stone

Answer 51

<5%

Question 52

Extracorporeal shock wave lithotripsy effective on

Answer 52

<2 cm stone

Question 53

Can be used to drain obstructed, infected, dilated kidney if catheters can’t pass through

Answer 53

Nephrostomy tube

Question 54

Indicated for staghorn calculi and bigger stones

Answer 54

Percutaneous nephrolithotomy

Question 55

Complication of percutaneous nephrolithotomy

Answer 55

Bleeding

Question 56

T/F. No need to assess renal function before treating a stone.

Answer 56

False (assess first!)

Question 57

For proximal ureteral stone, be it retroperitoneal or transperitoneal

Answer 57

Laparoscopy