ACUTE KIDNEY INJURY

Question 1

major characteristics of an AKI?

*prevented how?

Answer 1

oliguria
anuria
elevation of BUN and creatinine

patient care

Question 2

renal function tests?

Answer 2

urine output

• normal: 1000-2000 ml/d
• oliguria: <500 ml/d
• anuria: <50-100 ml/d
• hourly: 0.5 ml/kg/hr

BUN and creatinine

• normal BUN: 7-24 mg/dl
• normal creatinine: 0.6-1.5 mg/dl

Question 3

Na in AKI is high or low in the serum?

Answer 3

low, so lots of Na in the urine

normal Na levels: 20 meq/L, in AKI >20 meq/L

Question 4

FENa stands for, what is it?

Answer 4

fractional excretion of Na (FENa)

normal FENa is approx 1%

elements used in calculation of FENa is urine Na and Cr, serum Na and creatinine

Question 5

how to differentiate prerenal azotemia and AKI by using FENa?

Answer 5

prerenal: FENa <1%

in AKI: FENa >1%

Question 6

is this prerenal azotemia or AKI?

low FENa
volume depletion 
hepatorenal syndrome
contrast-induced nephropathy
rhabdomyolysis

Answer 6

prerenal azotemia

Question 7

is this prerenal azotemia or AKI?

FENa>1%, so a high FENa

Answer 7

AKI

Question 8

limitation of FENa?

Answer 8

diuretic use within past 24 hours, greater than natriuresis

Question 9

what are the lab results of in a hypovolemia?

BUN:Cr
urine specific gravity
urine Na
FENa?

Answer 9

high BUN:Cr
high urine specific gravity
low urine Na
FENa <1%

Question 10

main pathogenesis of AKI?

Answer 10

prerenal
-prerenal azotemia

renal
-acute tubular necrosis

post renal
-obstructive uropathy

Question 11

renal artery stenosis is an example of what type of prerenal azotemia?

Answer 11

selective renal ischemia

Question 12

acute tubular necrosis: surgical etiologies?

Answer 12

procedures requiring an aortic cross clamp

• AAA repair
• LE bypass procedure

cardiac surgery and cardiopulmonary bypass

• low perfusion
• blood cell products

Question 13

acute tubular necrosis: nephrotoxins

Answer 13

NSAIDs
ace inhibitors
heme pigments
antibiotics
-vancomycin

Question 14

do not prescribe ACE inhibitors to patients with…?

precautions with what meds?

Answer 14

bilateral RAS

ACE-Is and ARBs in a patient with marginal BP or volume status

Question 15

possible causes of renal insufficiency?

Answer 15

blood pressure too low
sepsis
ACE inhibitors

Question 16

what drug can induce AKI?

trough levels?

Answer 16

vancomycin

> 10 mg/L but <20 mg/L
*even if patient has underlying kidney disease, loading doses are still needed

Question 17

risk of AKI increased by what drugs?

Answer 17

Loop diuretics
IV contrast
Pip-tazobactam
vasopressors

Question 18

s/s of rhabdomyolysis?

Answer 18

lower back
muscle weakness
low urine output
dark red or brown urine