Nephrolithiasis

Question 1

Describe how furosemide can cause renal stones

Answer 1

Increases urinary calcium excretion

Question 2

True or false. Hyperparathyroidism can lead to nephrolithiasis.

Answer 2

True

Hyperparathyroidism increases calcium levels

Question 3

For patients trying to reduce their risk of kidney stones, should they increase or decrease their dietary intake of protein?

Answer 3

Decrease protein intake

Question 4

Urine pH in patients with struvite stones

Answer 4

pH>8

(infections thrive in alkaline conditions)

Question 5

Treatments (4) for cystine stones

Answer 5

Hydration

Alkalinize urine (potassium citrate/Urocit)

Penicillamine for patients who don’t respond to conservative measures

Annual renal US or KUB

Question 6

Most common type of renal stone

Answer 6

Calcium oxalate

Question 7

As well as increasing fluid volume, drinking this can help reduce a patient’s risk of nephrolithiasis

Answer 7

Lemonade (or anything else containing lemon/citrate)

Question 8

This type of kidney stone most commonly first presents in childhood around the age of 12

Answer 8

Cystine stones

Question 9

Is nephrolithiasis more common in males or females?

Answer 9

Males

(males 19%, females 9%)

Question 10

Patients with struvite stones have recurrent UTIs without e. coli but with these (3) bacteria present

Answer 10

Proteus (most common)

Klebsiella

Pseudomonas

Question 11

Which imaging type best shows uric acid stones?

Answer 11

CT scan.

(Uric acid stones are radiolucent, won’t show on x-ray)

(Ultrasound used to see hydronephrosis if stone is in kidney. If stone is in ureter, won’t see on U/S)

Question 12

Describe how topiramate can cause renal stones

Answer 12

Increases urine pH and decreases urine citrate levels

Question 13

Describe a duplicated collecting system

Answer 13

Extra renal pelvis and/or extra ureter

Question 14

Medication to help aid with passing of kidney stones by relaxing distal ureter

Answer 14

Alpha blockers (Tamsulosin) relax distal ureter in men and women

Question 15

Three treatment methods for uric acid stones

Answer 15

Restrict dietary purines

Urinary alkalinization (Sodium bicarb to dissolve stones in short term, Potassium citrate long term)

Allopurinol

Question 16

Dietary risk factors (7) for nephrolithiasis

Answer 16

Fluid intake (low)
Type of fluid (dark soda, tea)
Calcium
Protein
Oxalate
Sodium
Dietary patterns (confounds as FH)

Question 17

Treatment of renal stones induced by drugs indinavir and nelfinavir require acidification or alkalinization of the urine?

Answer 17

Acidification

Question 18

When and how to follow-up after kidney stone removal

Answer 18

Ensure passage of stone with imaging

Analyze stone/metabolic analysis to find cause

Follow up at six months, then annually, with KUB as recurrence rates high

Question 19

Nephrolithiasis symptoms

Answer 19

Often asymptomatic

Abrupt onset flank pain radiating to groin or testicles

Question 20

Most common renal abnormality that contributes to formation of kidney stones

Answer 20

Horseshoe kidney

(connected kidneys promotes urinary stasis = stone formation)

Question 21

Urinary risk factors (5) for nephrolithiasis

Answer 21

Low urine volume (biggest one)
Hypercalciuria
Hyperoxaluria
Hypocitraturia
Urine pH

Question 22

Medications (5) which can cause nephrolithiasis

Answer 22

Topiramate
Acetazolamide
Long term glucocorticoids
Indinavir
Triamterene

Question 23

Kidney stones larger than 2cm may require this invasive procedure

Answer 23

Percutaneous nephrostolithotomy

Question 24

Cystine stones can be diagnosed with the presence of two things in the urine. One is cystine, what’s the other?

Answer 24

Hexagonal crystals

Question 25

This type of kidney stone runs in families in an autosomal recessive pattern

Answer 25

Cystine stones

Question 26

This kidney abnormality causes unilateral obstruction that prevents kidney drainage

Answer 26

Congenital UPJ obstruction

Question 27

These types of kidney stones are large and have a characteristic staghorn appearance

Answer 27

Struvite stones

Question 28

Procedure to view and remove stones in between kidney and bladder

Answer 28

Ureteroscopy May leave stent in post-stone removal to prevent ureter collapse

Question 29

Kidney stones smaller than this size have an 80% chance of passing on their own

Answer 29

<5mm

Question 30

Biggest risk factor for calcium containing kidney stones

Answer 30

High levels dietary oxalates

Question 31

Technique using sound waves to break up large renal stones to ease passing

Answer 31

Lithotripsy (aka ESWL = extracorporeal shock wave lithotripsy)

Question 32

Pharmacologic therapy for calcium containing stones

Answer 32

Low dose thiazides (HCTZ, chlorthalidone) Potassium citrate (increase citrate and replace K+ lost form thiazides) Cholestyramine, Calcium carbonate (if hyperoxaluria)

Question 33

Most definitive imaging for nephrolithiasis

Answer 33

CT abdomen/pelvis WITHOUT contrast

Question 34

Area of US with highest prevalence of nephrolithiasis

Answer 34

South Eastern US

Question 35

Name the two types of radiopaque kidney stones

Answer 35

Calcium containing stones (calcium oxalate and calcium phosphate) Struvite stones (Cystine stones are moderately radiopaque)

Question 36

What is the average time to pass kidney stones sized 2-4mm?

Answer 36

12.2 days (95% pass in 40 days)