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P&T Block 5 Renal > L63 > Flashcards

Flashcards in L63 Deck (26)
1

Name 5 causes of Ca kidney stones

1. ↑U Ca (↑P Ca)
2. 1ary hyperPT
3. ↓U citrate
4. ↑U uric acid, cysteine
5. RTA - can't acidify urine, basic urine supports Ca deposition

2

TEST Q: why does hypo-citrat-uria cause kidney stones?

Citrate inhibits formation stones!

3

What is the most common type kidney stone (composition)?

Ca oxalate - look for diamond squares or 2 fans
See on XR (think: Ca in bone)

4

Does high or low urine volume facilitate the formation of stones?

Low - more [urine]

5

Explain the pathophys of Ca oxalate stones - ↓ in what 3 things ↑chance of these?

Ca ox stone = +
Urine has proteins, GAGs and citrate: all negative
+ bind - to keep everything soluble
Decrease in any of the (-) means + stone binds the neg charged endothelium

6

Clinical presentation of kidney stones

Acute pain, worsening
CVA tender // flank pain radiates to groin
Waxes + wanes
Feel need to pee but nothing comes out
Microscopic hematuria
N+V+fever
ALL symptoms go away suddenly if you pass stone (into ureter)

7

Why do you get micro hematuria w/ kidney stones?

Destruction of urothelium

8

Imaging options for kidney stones

CT - see level of the blockage, 1st choice for eval b/c will never miss it
US - quick rule in/out

9

What stones are pts with chronic diarrhea at risk for?

Ca ox - loose tight jxns in GI
Hyper absorb oxalate

10

What are the higher risk stones (more likely to recur)?

Uric acid
Cystine
Struvite

11

Dietary treatment for kidney stones

↑Fluids = more dilute urine
↓Protein
Limit Na
NO CHANGE CA INTAKE

12

Why don't you limit Ca intake for kidney stone pts?

Low Ca would stimulate PTH to increase reabsoprtion of Ca and oxalate from GI
You want NEITHER of those things

13

Treat hyperCa

1. Thiazide + Na restrict = ↑Ca reaborption and may lead to bone mineralization
2. Amiloride = K sparing = ↑Ca reabsorbed at CD
3. K citrate or PO4 (prevent hypocitrate)

14

Why do you get uric acid stones?

Over produce it -> over excrete it
+ Dehydration = ↓urine vol

15

Are uric acid stones visible on XR?

No - radiolucent

16

Do uric acid stones form in a basic or acidic urine?

Acidic, pH

17

3 scenarios of ↓urine volume that can lead to uric acid stones

Exercise
Dehydration
Chronic diarrhea

18

Disorders that produce too much uric acid -> stone

Gout
Myeloprolif

19

What are struvite stones make of? Cause?

Mg NH4 PO4 stones
Bacteria: proteus, pseudomonas, kleb

20

Are struvite stones made in an acidic or basic urine?

Basic U pH

21

What is cystinuria?

Genes mutated - can't reabsorb + AAs
- Lysine
- Ornithine
- Arginine

22

What do the crystals in cystinuria look like?

Ground glass, 6 sided

23

Treat cystinuria

Hydration
Alkalinization

24

What drug can cause stones? Type of stone + treatment

Protease inhibitors (indinvir, tenofavir)
Accumulate in the renal pelvis - crystals made of the drug
Treat w/ hydration

25

Treat chronic uric acid stones

Allipurinol = uric acid inhibitor (gout)
K citrate

26

Treat chronic struvite stones

Surgery
Antibiotics vs inciting organism