Goljan renal 2

Question 1

BUN

creatinine = end product of creatine metab

Answer 1

urea filtered and reabs in prox tubule

creatinine filtered in kidney not reabs but secreted

Question 2

normal bun

normal creatinine

normal bun: creatinine

Answer 2

bun = 9

creatinine = 1 mg/dL

10

Question 3

prerenal azotemia

Answer 3

due to decr CO
decr GFR

CHF
MI
cardiomyopathy
hypovolemia

Question 4

why BUN/creatinine ratio incr in prerenal azotemia

Answer 4

decr RBF, decr GFR

gives prox tubule more time to reabs more urea than normal
incr prox tubule reabs of urea

decr creatinine clearance, incr serum creatinine

Question 5

BUN/creatinine ratio for prerenal azotemia

Answer 5

> 15

Question 6

oliguria

renal tubular casts

Answer 6

acute renal failure

Question 7

acute renal failure affects BUN and creatinine how?

Answer 7

equally both because both cannot be filtered in kidney

incr proportionally so ratio = 10 (normal)

Question 8

acute renal failure most common due to

Answer 8

ischemic acute tubular necrosis

Question 9

when CO decr, oliguria

Answer 9

prerenal azotemia or ischemic ATN

but look at BUN: creatinine ratio to separate

Question 10

most common cause of ischemic ATN

Answer 10

prerenal azotemia

Question 11

ischemic ATN

Answer 11

coagulation necrosis –> basement membrane cells sloughed off–> block lumen –> oliguria

urine will show renal tubular epithelial cells/casts

Question 12

why ischemic ATN so bad?

Answer 12

not only killing tubular cells but also damage basement membrane

destroying structure of tubule, and cannot regenerate tubular cell if no basement membrane

Question 13

2 parts of nephron most susceptible to ischemia

ischemic in ischemic ATN

Answer 13

straight prox tubule

thick ascending limb in medullary segment (Na/K/2Cl)

Question 14

nephrotoxic tubular necrosis due to

Answer 14

aminoglycosides, IV pyelograms
- because targets prox tubule

basement membrane still intact–> better than ischemic ATN

Question 15

GFR in older patient?

Answer 15

GFR decr and creatinine clearance decr

Question 16

give older patient drug with no nephrotoxicity in same amount as young person with normal GFR,

Answer 16

killing older patients

Question 17

pyelonephritis vs. lower URI

Answer 17

45:49