AKI

Question 1

Acute tubular necrosis or ATN

Answer 1

most common cause of acute renal failure in hospitalized pts

see abrupt renal ischemia from shock, sepsis, crush injuries and medications that decrease renal flow.

Question 2

treatment of ATN

Answer 2

IVF replacement and treatment of reasons for renal ischemia

Question 3

allergic interstitial nephritis AIN

Answer 3

nephritis that affects interstitum of kidneys and surrounding renal tubules.

AIN causes are infections and reactions to medications such as nafcillin, methicillin, NSAIDS, rifampin, sulfa drugs, quinolones, diuretics, allopurinol, phenytoin.

also can be caused by Legionella or Streptococcus, systemic disease like SLE and sarcoidosis and Sjogren’s

Question 4

treatment of AIN

Answer 4

supportive therapy, and stopping offending cause

Question 5

labs seen on AIN

Answer 5

eosinophilia, rash, high WBC in urine
see AKI, can see pyuria, hematuria, WBC casts

can see urinary eosinophils
renal biopsy shows: inflammatory infiltrate and edema

Question 6

clinical features of AIN

Answer 6

see allergic symptoms (urticaria) and new drug exposure

Question 7

most common cause of AIN

Answer 7

drugs.

PPI, NSADS and antibiotics and this happens about weeks or months after primary exposure. Rapidly develops on second exposure

Question 8

triad of AIN:

Answer 8

rash, fever, eosinophilia but also can no symptoms or not have all three

urinary eosinophils only seen 40% of the time.

Question 9

when do we see renal involvement of RA (with renal vasculitis or glomerulonephritis or membranous nephropathy)

Answer 9

see this is someone with advanced joint destructive dx

Question 10

Renal atheroembolic dx risk factors

Answer 10

aortic arteriography, angioplasty, or surgery

Question 11

clinical features of renal atheroemoblic dx (cholesterol emboli to renal)

Answer 11

subacute onset AKI (1-2 weeks after procedure
active urinary sediment (hematuria, eosinophilia, WBCs, mild proteinuria)

Peripheral eosinophilia, and low complement levels

cyanosis or gangrene of toes with intact pulses

livedo reticularis rash

Question 12

Treatment of cholesterol emboli

Answer 12

supportive and directed at 2nd prevention against CAD with statin, aspirin, BP control and smoking cessation

Question 13

when does cholesterol emboli AKI and livedo reticularis rash occur after procedure?

Answer 13

it happens 1-2 weeks after.

Question 14

mottled lacy rash is

Answer 14

livedo reticularis rash

Question 15

Causes of crystal induced AKI

Answer 15

acyclovir
sulfonamides (sulfadiazine)
methotrexate
ethylene glycol
protease inhibitors
uric acid (tumor lysis syndrome)

Question 16

clinical presentation of crystal induced AKI

Answer 16

usually asymptomatic
AKI<7 days after starting drug
UA: hematuria and pyuria and crystals
increased risk for volume depletion and CKD

Question 17

management of crystal induced AKI

Answer 17

discontinuation of drug
volume repletion
loop diuretic

Question 18

how does crystal induced AKI occur?

Answer 18

see poorly soluble drugs can precipitate into crystals in the renal tubules

seen with sulfadiazine

Question 19

sulfadiazine crystal induced AKI on UA

Answer 19

see acidic urinary pH (also seen with uric acid, sulfonamides and methotrexate)

see needle shaped, rosettes, or “clumped stacks of wheat” crystals

see hematuria and pyuria too.

see flank pain

Question 20

prevention and treatment of sulfadiazine induced AKI would be

Answer 20

adequate hydration 3l/day and alkalinization of urine to increase solubulity (ph>7.5)

Question 21

what predisposes the formation of crystals in the urine?

Answer 21

high doses of drugs, dydration (increased intratubular concentration) and acidic urinary pH

Question 22

is ultrasound helpful for diagnosing crystal induced AKI?

Answer 22

not really. can’t confirm diagnosis

Can show normal, or sludge or small calyceal stones (due to sulfonamide precpitation) or reveal hydronephrosis in rare cases)

but findings are likely nonspecific and unlikely to change management.

Question 23

how to prevent AKI in the treatment of HSV encephalitis

Answer 23

Acyclovir is a very poorly soluble medication and you can have AKI develop within 48 hrs of using this medication and so need to prevent this happening.

will see hematuria, pyruia, and birefringent needle shaped crystals on urinalysis.

Can give loop diuretics ot help flush crystals from renal tubules.

Question 24

FeNA is calculated by:

Answer 24

(urine sodium x serum creatinine) / (serum sodium x urine creatinine) to get a percentage

<1% pre renal etiologies of acute AKI need to be considered

1-2% intrarenal

> 2% consider post renal or obstructive causes

Question 25

intrarenal causes of AKI are

Answer 25

diabetic and hypertensive nephropathy

allergic interstitial nephritis

Question 26

post renal causes of AKI

Answer 26

BPH and nephrolithiasis and masses

Question 27

pre renal causes of AKI

Answer 27

meds and dehydration

Question 28

If there’s hematuria in the blood and dysmorphic cells then consider

Answer 28

renal biopsy

Question 29

if undifferentiated causes of AKI consider getting a

Answer 29

U/S of renal

not renal biopsy unless concerned about glomerulonephritis

Question 30

best way to prevent CIN in someone with AKI?

Answer 30

give NS at 3ml/kg hourly for one hour prior to proceure and 1 ml/kg hourly for 6 hours following.

do this over stopping ACEi

Question 31

fenofibrate nephrotoxicity occurs

Answer 31

> 6 months use

see a rise in serum cr after initiation and sediment is bland and no significant proteinuria.