Lecture 15 - Kidney Stones Flashcards

1
Q

The vast majority of nephrolithiases (about 80%) are composed of ______.

About 3-13% are composed of ____ ____.

Only about 1-2% are composed of _____ –> keep in mind this is an autosomal ______ disease, so symptoms are evident in ______ (children or adults?).

______ stones (triple phosphate) are associated with chronic infections with bacteria that split _____ into _____ and phosphate.

A

Calcium

Uric acid

Cystine

Autosomal Recessive

Children (median age of onset = 12)

Struvite

Urea into NH3

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2
Q

Nephrolithiases are more common in ______ (which gender?) and in ______ (which ethnicity?). The mean age for appearance of kidney stones is in the ______ decade of life. Keep in mind there’s a 40% chance of recurrence by 5 years and 75% by 20 years after the first.

A

Males

Whites

4th decade of life

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3
Q

Though multifactorial, there is a genetic component to acquiring kidney stones, so look to patients’ ______ ______!

A

Family Histories

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4
Q

Kidney stones can have Homogeneous or Heterogeneous _______, so basically what initially seeds the crystal may or may not be what forms the bulk of the crystal.

In some cases, ______ plaques can form and act as points of ______ for crystal formation –> these plaques are Calcium phosphate depositions in the interstitium of the kidney that break into the renal pelvis.

A

Nucleation

Randall’s plaques

Nucleation

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5
Q

The major inhibitor of Ca++ stone formation is ______, which complexes with Ca++ to keep it in solution.

A

Citrate

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6
Q

Some GI disease that cause malabsorption of nutrients can lead to INCREASED absorption of ______ –> this of course increases the likelihood of forming ______ ______ stones.

A

Oxalate

Ca++ Oxalate

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7
Q

Patients with ______ bladder (or _____ ____ injury leading to _____ bladder) are at higher risk of UTI. Which stones are they most at risk for?

A

Neurogenic bladder

Spinal Cord injury leading to Neurogenic bladder

Struvite stones

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8
Q

Patients with Gout, ______, and _____ are at higher risk of forming Uric acid stones.

A

Diabetes

Obesity

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9
Q

For urine pH < 5.5 –> suspect ______ ____ stones.

For urine pH between 6.5 and 7 –> suspect ____ ____ stones.

For urine pH > 7.0 –> suspect _____ stones.

A

Uric Acid

Ca++ Phosphate

Struvite

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10
Q

Specific gravity (SG) of water is 1.0, and the most concentrated urine SG is about 1.03. What can patients do to lower the SG of their urine?

A

Hydrate!

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11
Q

With men putting out about 20mg/kg and women putting out about 15mg/kg, measuring ______ with urine samples will help determine if you’ve collected an adequate sample.

A

Creatinine

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12
Q

Cystine crystals are ______ (what shape?) and are NEVER normally in urine.

A

Hexagonal

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13
Q

Struvite crystals have a characteristic “_____ ____” appearance.

A

Coffin Lid (sort of like emerald cut diamonds.)

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14
Q

Envelope or barbell shapes are characteristic shapes of ____ _____ crystals.

A

Ca++ Oxalate

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15
Q

Uric acid crystals have a characteristic ______ or football shape.

A

Rhomboid

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16
Q

Uric acid is radioluscent, so it is not very visible on _____; instead, you would need a CT scan.

A

x-ray

17
Q

Stones up to about ____ or ____ mm are likely to pass on their own. Stones > ____ mm will not likely pass on their own. Stones between ___ and ____ mm MIGHT pass on their own.

A

5 or 6mm –> likely to pass

> 10mm –> probs not

Between 6 and 10mm –> Maybe

18
Q

Hypercalciuria in men is classified as > _____ mg /day. In women: > ____mg/day.

A

Men: > 250mg/day

Women: > 200mg/day

19
Q

______ hypercalciuria is the most common cause of stone formation.

A

Idiopathic

20
Q

Oxalate normally binds _____ in the intestinal lumen which prevents its absorption, but with malabsorption diseases, there’s more FFA in the intestinal lumen that binds ____ –> This leaves Oxalate unbound and capable of being absorbed.

A

Ca++

Ca++

21
Q

There are bacteria in the large intestine that use ______ as a substrate for metabolism –> the absence of these bacteria may contribute to formation of stones.

A

Oxalate

22
Q

Oral _______ can be given to help reduce oxalate absorption. Keep in mind Ca++ can be given as well.

A

Cholestyramine

23
Q

Primary Hyperoxaluria (PHO) is an uncommon, autosomal _____ disease in which patients are deficient in one of the liver enzymes that metabolize ______ to either _____ or _____ –> this pushes the metabolism to form more Oxalate instead.

A

Recessive

Glyoxalate

Glycolate or Glycine

24
Q

As children with PHO develop worsening CKD and ESRD, their GFR decreases. How does this affect systemic Oxalate?

A

Oxalate will increase in the blood as less is filtered, and this can lead to Oxalate deposits systemically.

25
Q

Citrate is reabsorbed in the ______ of the nephron. The most important regulating factor is _____.

A

PCT

pH

26
Q

For patients with pure Uric acid stones, what is the best treatment?

A

Alkalinize the urine

27
Q

Treatment for Cystine stones is medication that prevents the precipitation of Cystine’s dissociation product: _______. These medications are _______, ______, and _______.

A

Cysteine

Penicillamine, Tiopronin, Captopril

28
Q

Which condition can be treated with high dose Thiazide diuretics?

A

Hypercalciuria –> thiazide diuretics decrease urine Ca++