Acute Kidney Injury

Question 1

four major risk factors for acute kidney injury

Answer 1

age >75, DM, preexisting chronic kidney disease, CHF

Question 2

Azotemia

Answer 2

The build up of abnormally large amounts of nitrogenous waste products in the blood

Question 3

anuria

Answer 3

Urine output < 100 mL/day

Question 4

How common is acute kidney injury?

Answer 4

7% of hospitalized patients and 66% of ICU patients

Question 5

Where is ammonia from protein breakdown processed into urea?

Answer 5

the liver

Question 6

Which of the following increase ammonia/BUN due to increase in protein breakdown: burns, tetracycline, steroids, fever, catabolic state?

Answer 6

all of them. GI also increase BUN but it is due to breakdown of hemoglobin

Question 7

When will the BUN decrease?

Answer 7

liver failure

Question 8

How does a decreased GFR lead to an increased BUN?

Answer 8

Decreased flow through the glomerulus and slower transport time allows more BUN to be resorbed at the level of the PCT

Question 9

Relationship between creatinine and muscle mass

Answer 9

more muscle mass the higher the creatinine. The lower the muscle mass the lower the creatinine

Question 10

What drugs can block the secretion of creatinine at the DCT?

Answer 10

cimetidine and trimethoprim

Question 11

BUN/Cr ratio

Answer 11

Normal is 10-20:1

Elevated is > 20:1

Question 12

Main problem with prerenal failure

Answer 12

lack of blood flow to the glomerulus

Question 13

What does the kidney do to compensate for lack of blood flow due to prerenal failure?

Answer 13

increases Na+ reabsorption

Question 14

Lab results of prerenal failure

Answer 14

BUN/Cr ratio >20:1, urine Na+ <1%

Question 15

Which of the following drugs should you avoid with prerenal failure: NSAIDs, glucophage, diuretics, IV contrast, ACEI/ARB?

Answer 15

avoid all depending on patient

Question 16

What drugs can cause postrenal failure?

Answer 16

anticholinergics (Benadryl-diphenhydranine)

Question 17

Causes of acute glomerulonephritis

Answer 17

post streptococcal, systemic illness (SLE, Wegeners, Goodpastures)

Question 18

Urinalysis results for acute glomerulonephritis

Answer 18

red cell casts and significant proteinuria

Question 19

Most common cause of acute interstitial nephritis

Answer 19

medication use

Question 20

Signs and symptoms of acute interstitial nephritis

Answer 20

maculopapular rash, fever, arthralgias. Eosinophils in the urine

Question 21

Most common cause of acute intrinsic renal injury

Answer 21

acute tubular necrosis due to either ischemia, sepsis, nephrotoxic drugs

Question 22

What fails to fxn in acute tubular necrosis?

Answer 22

tubules

Question 23

Urinalysis assocated with acute tubular necrosis

Answer 23

elevated urine sodium >20, low urine SG/Osm < 450, and muddy brown granular casts

Question 24

Major cause of acute tubular necrosis secondary to toxins

Answer 24

aminoglycosides (gentamicin, amikacin)

Question 25

Measures to prevent contrast nephropathy

Answer 25

hydrate pre and post procedure w/normal saline, maybe Mucoymyst, stop metformin (glucophage) the day of contrast and 48hrs after

Question 26

Interpretation of FENa

Answer 26

Prerenal FENa < 1%

Intrinsic FENa is > 2%

Question 27

Urine particles associated with acute interstitial nephritis

Answer 27

WBCs and WBC casts