Nephrolithiasis lecture

Question 1

Supersaturation may result from:
↑ excretion of poorly soluble substances in addition to other confounding factors (i.e., low urine volume, abnormal urine pH)

Answer 1

Nephrolithiasis

Question 2

calcium oxalate stones

Answer 2

MOST COMMON**

Question 3

calcium oxalate*
struvite “stag horn”
uric acid
cystine

Answer 3

types of urinary stones

Question 4

these stones are radiopaque

Answer 4

Calcium oxalate

Question 5

______ stones frequently have smooth-edged ground-glass appearance.

Answer 5

Cystine

Question 6

Idiopathic hypercalciuria
Primary hyperparathyroidism
Hypocitraturia
Hyperuricosuria
Renal tubular acidosis
Dietary hyperoxaluria
Enteric hyperoxaluria
Primary hyperoxaluria
Colon resection, ileostomy
Habit, environment

Answer 6

causes of calcium stones

Question 7

produced by UTI with urease-producing bacteria
usually large stones (> 2 cm)
Proteus, Klebsiella, Pseudomonas and Enterobacter spp.
treatment: prevent UTIs

Answer 7

Struvite stones

Question 8

caused by low (6 with potassium citrate 20 mEq BID

Allopurinol and low-purine diet (↓ fish, shellfish & meats)

Answer 8

Uric acid stones

Question 9

autosomally recessive inherited abnormalities
treatment: ↑ urine volumes to 3 L daily and ↑ urine pH to >7 with potassium citrate 20 mEq BID
occasionally chelating agents may be used (i.e., tiopronin)

Answer 9

Cystine stones

Question 10

Geographic factors:
high humidity
high temps

Answer 10

Kidney stones

Question 11

Sedentary occupations
High animal protein and high salt intake
Genetic factors

Answer 11

Risk factors for Kidney stones

Question 12

FH 1st degree relative (calcium stones)
Concurrent medical conditions
bowel resection
gout
hyperthyroidism
hyperparathyroidism
sarcoidosis

Answer 12

Risk factors for kidney stones

Question 13

Most common:
Unilateral flank pain
Sudden onset 
Renal colic (waxes and wanes)
Hematuria

Answer 13

signs and symptoms of kidney stones

Question 14

Less common:
Asymptomatic
Vague abdominal pain
Acute abdominal or flank pain (constant)
Nausea
Persistent urinary frequency w/o  evident infection (stone at ureterovesical junction)
Difficulty urinating
Penile pain or testicular pain
Acute renal insufficiency due to obstruction

Answer 14

Kidney stones

Question 15

Nephrolithiasis gold standard diagnostic…

Answer 15

non contrast CT scan

Question 16

X ray will only detect which type of stone?

Answer 16

Calcium

*will miss uric acid and cysteine stones

Question 17

Which diagnostic should you use in a pregnant woman with kidney stones?

Answer 17

Ultrasound

Question 18

have a laminar rugged appearance, and are often full casts of the renal pelvis and calyces, the so-called “stag horn” conformation.

Answer 18

Struvite stones

Question 19

Most patients with nephrolithiasis are treated with….

Answer 19

NSAIDs and opioids*
hydration
strain urine

Question 20

Likelihood of spontaneous stone passage depends on…

Answer 20

size

location

Question 21

medical expulsive therapy (MET)

• alpha blockers
• CCBs

Answer 21

can facilitate stone passage

Question 22

Acute renal failure
Urosepsis
Urinary obstruction (anuria)
Unyielding pain +/- nausea/vomiting
Anatomic abnormalities or solitary kidney
Concomitant pyelonephritis
Stone >10 mm**
Have not passed stone after 4-6 weeks**

Answer 22

Consult with urology

Question 23

Shock wave lithotripsy (SWL)
Percutaneous nephrolithotomy (PNL)
Rigid and flexible ureteroscopy (URS) ± stent placement

Answer 23

Surgical techniques to remove stones

*10-20% require

Question 24

Lower urine supersaturation by increasing fluid intake is key!
avoid dehydration & maintain urine volume of more than 2L

Answer 24

stone prevention

Question 25

↓ oxalate intake (i.e., rhubarb, spinach, many nuts & seeds)
↓ animal protein intake
↓ sodium intake
↑ fluid intake

Answer 25

diet changes to help prevent calcium stone formation