AKI-Clinic VIR

Question 1

definition of kidney injury/disease

Answer 1

alteration in kidney structure or function such than GFR is less than 60

Question 2

chronic kidney disease must last greater than or equal to?

Answer 2

3 months

Question 3

limitations to serum creatinine as measure of kidney function

Answer 3

does not truly reflect decrease in GFR until 3 days after insult begins; affected by body mass, hydration, etc.

Question 4

signs of acute vs. chronic kidney disease

Answer 4

acute: decreased urine output; chronic: small, echogenic kidneys on US

Question 5

most common cause of AKI in community is ____, in hospital is _____

Answer 5

pre-renal (ischemia or nephrogenic); intra-renal (especially tubular injury)

Question 6

causes of decreased renal perfusion (pre-renal ischemia)

Answer 6

low ECF volume (GI loss, hemorrhage, diuretics); altered blood flow (sepsis, heart failure, cirrhosis, hypercalcemia, medications, vascular dz)

Question 7

causes of acute tubular necrosis (intra-renal)

Answer 7

ischemic tubular injury (from pre-renal cause oftentimes) or nephrotoxins (cisplatin, aminoglycosides, heme, iodinated radiocontrast)

Question 8

causes of post-renal injury

Answer 8

prostate hypertrophy, kidney stones

Question 9

diagnostic approach to evaluating AKI

Answer 9

1. history, 2. physical exam, 3. exclude urinary tract obstruction, 4. examine urine

Question 10

what component of the physical exam is particularly important when dx AKI

Answer 10

volume status: are there signs of volume depletion (skin turgor, orthostatic hypoTN)? If so, then likely PRE-RENAL

Question 11

how do you exclude post-renal causes of AKI?

Answer 11

insert foley catheter and observe no change in urine output; renal US demonstrates cortex of normal thickness, no dilation in collecting system

Question 12

urine sediment will look ____ if pre-renal injury

Answer 12

normal

Question 13

causes of RBC casts and proteinuria in the urine

Answer 13

glomerulonephritis, vasculitis, TMA, atheroemboli

Question 14

causes of WBC casts and eosinophils in urine

Answer 14

pyelonephritis, interstitial nephritis, atheroemboli, glomerulonephritis

Question 15

cause of renal tubular endothelial cells and dark muddy casts in urine

Answer 15

ATN

Question 16

the most important distinction to make when analyzing urine indices is between ____ and ____

Answer 16

pre-renal and ATN

Question 17

describe the SG, osmolality, sodium, FENa, and FEUrea for pre-renal tubular injury

Answer 17

SG >1.020, osmol >500, Na <35% (so basically higher SG and osmolality, lower excretion of sodium and urea)

Question 18

describe the SG, osmolality, sodium, FENa, and FEUrea for ATN

Answer 18

SG ~1.010, osmol 30, FENa >2%, FEUrea >50% (so basically lower SG and osmolality, higher excretion of sodium and urea)

Question 19

why is FE (fractional excretion) used to measure sodium and urea excretion?

Answer 19

unaffected by water reabsorption

Question 20

how to calculate FENa

Answer 20

Na excreted/Na filtered X 100 = (UNa X SCr)/(UCr X SNa) X 100

Question 21

when should FE Urea be used instead of FE Na?

Answer 21

when diuretics have been given in past 24-48 hours (b/c urea is reabsorbed before you get to action of diuretics)

Question 22

when might FE Na be greater than 2% in a setting other than ATN?

Answer 22

CKD, recent diuretic use

Question 23

when might ATN present with an FE Na of <1%?

Answer 23

if it is from radiocontrast, is early (nonoliguric), or is co-occuring with chronic pre-renal condition

Question 24

what is an example of an intra-renal process that causes an FE Na of <1%?

Answer 24

glomerulonephritis/vasculitis

Question 25

tx of pre-renal kidney injury

Answer 25

normal saline + stop diuretics

Question 26

how do NSAIDs decrease blood flow to the kidneys?

Answer 26

block intra-renal prostaglandins, attenuating afferent dilation and causing a reduction in GFR

Question 27

iodinated contrast from a CT can result in rapid onset?

Answer 27

ATN (nephrogenic)

Question 28

these drugs can cause interstitial nephritis

Answer 28

antibiotics, NSAIDs, diuretics

Question 29

tx of interstitial nephritis

Answer 29

steroids

Question 30

nephrostomy tube

Answer 30

percutaneous drain placed in renal collecting system; used to decompress obstruction, divert fistula, access for other procedure

Question 31

enter back at 30-40 degree angle from spine to avoid?

Answer 31

colon, liver, spleen

Question 32

go into the ____ calyx

Answer 32

lower (it has smaller vessels)

Question 33

nephroureteral stent

Answer 33

allows for drainage from renal pelvis to bladder & maintains access for future intervention

Question 34

ureteral “JJ” stent

Answer 34

allows for drainage from renal pelvis to bladder & completely internalized

Question 35

complications of ureteral stents

Answer 35

hemorrhage, PTX, puncture, urinoma, AV fistula, cath malfunction (clogged), urosepsis (so pre-tx with ABX)