Nephrolithiasis

Question 1

what type of crystal is this?

1. what is the pH of the urine?
2. what is the other presentation?
3. treatment:

Answer 1

These are calcium oxalate crystals

1. their formation is NOT dependent on the pH of the urine
2. they can also present as “dumbells”
3. treatment:
   
   1. refrain from eating spinach, nuts
   2. normal/increased dietary calcium intake

Question 2

What type of crystal is this?

forms in _____ urine

can also look like ______

Answer 2

This is a calcium phosphate crystal

it forms in alkaline urine

can also kinda look like a badmittin birdie

Question 3

what is this?

what type of stone does it form?

forms in ______ urine

Answer 3

This is a magnesium ammonium phosphate

it forms the basis of struvite stones

“coffin lids”

they only form in alkaline urine

Question 4

what type of crystals are these?

they form in _______ urine

Answer 4

Uric Acid crystal

uric acid crystals only form in acidic urine

Question 5

what is this?

what is there characteristic shape?

what is it pathonomonic of?

develops in _____ urine

Answer 5

Cystine Crystals

they have a characteristic hexagonal shape

it is pathonomonic of cystinuria

sucker!!! the pH doesn’t matter for the formation of these crystals

Question 6

What are the risk factors for developing kindey stones?

1. what are promoters?
2. what are inhibitors?

Other factors?

Answer 6

What are the risk factors for developing kindey stones?

1. what are promoters? calcium, oxalate, uric acid
2. what are inhibitors? citrate

Other factors? low fluid intake, low urine volume, personal history, family history, frequent UTIs (struvite stones), Enhanced enteric oxalate absorption (caused by shortening of bowels)

Question 7

innervation of the kidneys:

sympathetic

parasympathetic:

Answer 7

kidney

sympathetic: T10-11
parasympathetic: S2-S4

Question 8

Innervation Sympathetic/parasympathetic

1. upper ureter
2. middle ureter
3. lower ureter

Answer 8

Innervation Sympathetic/parasympathetic

1. upper ureter T11-12/vagal
2. middle ureter: T12-L1/vagal
3. lower ureter: L1-L2/ S2-S4

Question 9

What is the imaging study of choice to detect stones and obstructions?

Answer 9

nonContrast helical CT Scans are the imgaging study of choice for stones and obstructions

Question 10

What is the first choice for Acute management of a stone?

Answer 10

IVF if unable to tolerate oral hydration

Pain Medications (NSAIDs)

Medical Expulsive Therapy

Question 11

What determines if a stone will pass?

Answer 11

The size and location of a stone are the determinants for whether a stone will pass or not.

1. Size
   
   1. <4 usually passes
   2. 5-9 progressive decrease in pass rate
   3. >10 unlikely to pass
2. Location:
   
   1. proximal ureteral less likely to pass
   2. ureterovesical junction is more likely to pass

Question 12

A patient has hypercalciuria as a risk factor.

What steps can we take to target and reduce this as a risk factor?

Answer 12

We want to decrease the amount of calcium in the urine

do this by:

low salt

thiazide- make sure they maintain their hydration

Normal calcium diet

Question 13

How can we target hyperoxalaturia?

Answer 13

we want to decrease the oxalate that is in the urine

go on a low oxalate diet: refrain from eating nuts and spinach

normal/increased calcium intake

Question 14

how do we target the risk factor of hypocritraturia?

what type of stones are these pt. at risk for?

Answer 14

we want to increase the amount of citrate in the urine.

we can supplement their citrate but it may increase the pH of the urine which increases the risk for developing stones that contain phosphate (calcium phosphate or magnesium ammonium phosphate)

pt with hypocitraturia are at risk for developing

calcium oxalate stones