AKI

Question 1

what is an AKI

Answer 1

abrupt decline in renal function (GFR) occurring over hours to days, sometimes over weeks, with the inability to maintain and regulate fluid, electrolyte and acid-base balance

Question 2

what labs are associated with AKI

Answer 2

associated with accumulation of waste products (urea and creatine)

Question 3

normal urine output

Answer 3

> =1200ml/d

Question 4

anuria urine output

Answer 4

<50ml/d

Question 5

oliguria urine output

Answer 5

<500ml/d

Question 6

non-oliguria urine output

Answer 6

> 500ml/d

Question 7

KDIGO definition of AKI

Answer 7

• SCr increase by >=26.5 mmol/L within 48h or
• SCr increase to >=1.5x baseline within 7d or
• Urine Vol <0.5ml/kg/h for >=6h

Question 8

causes of AKI

Answer 8

• intravascular volume depletion
• drugs (NSAIDs, ACEi, ARBs, Contrast media, ahminoglycosides, amphotericin B, antivirals, Chemo)
• infections
• cardiac
• surgery

Question 9

pre renal AKI

Answer 9

resulting from decrease renal perfusion (most common in hospital) due to:
- volume depletion; or
- reduced cardiac output; or
- renal hypo perfusion

Question 10

intrinsic AKI

Answer 10

result of structural damage within kidney due to:
- acute tubular necrosis (most common)
- acute interstitial nephritis
- glomerular damage
- vascular damage

Question 11

post renal AKI

Answer 11

caused by obstruction of urine flow

Question 12

risk factors for AKI

Answer 12

• > 60yo
• female
• acute infection
• pre existing chronic respiratory or CVD
• dehydration / vol depletion
• preexisting CKD -> AoCKD

Question 13

clinical presentation of AKI

Answer 13

• reduced urine output
• peripheral edema
• flank pain
• abnormal labs (elevated SCr, BUN, K; presence of WBC, RBC, crystals in urine; abnormal SG, FeNA, urine osmolarity)

Question 14

possible causes of volume depletion

Answer 14

• hemorrhage
• GI losses (vomit/diarrhea)
• Urinary losses (over diuresis, DI)
• burns, peritonitis
• decrease effective volume (cirrhosis)
• peripheral vasodilation (sepsis, vasodilator)

Question 15

possible causes of reduced cardiac output

Answer 15

• sepsis
• CHF
• MI
• Pericardial tamponade
• Acute PE

Question 16

possible causes of renal hypoperfusion

Answer 16

• Bilateral renal artery occlusion (thrombosis, emboli, stenosis)
• medications (ACEi, NSAIDs, calcineurin inhibitors, radiocontrast media, vasopressors)

Question 17

diagnosis and evaluation for pre renal AKI

Answer 17

• pt hx (GI loss, diuresis)
• physical exam (orthostatic hypotension, tachycardia, poor skin turgor)
• central venous pressure (volume status of heart)
• urine test (SG, osmolarity, FeNa)

Question 18

Management of AKI

Answer 18

• reverse etiologic factors (treat pre-renal causes)
• use vasopressors with fluids in pt w vasomotor shock
• supportive care

Question 19

possible causes of acute tubular necrosis

Answer 19

• ischemic (hypotension, vasoconstriction)
• nephrotoxins (contrast dyes, heavy metals, amphotericin B, Aminoglycosides, organic solvents)
• endogenous toxins (hemoglobin, myoglobin)

Question 20

possible causes of acute interstitial nephritis

Answer 20

• drugs (penicillin, ciprofloxacin, sulphonamides)
• infections (viral and bacterial)

Question 21

possible causes of glomerular damage

Answer 21

• SLE (lupus, nephritis)
• rapidly progressive glomerulonephritis (GN)
• post streptococcal GN

Question 22

possible causes of vascular damage

Answer 22

• Vasculitis, polyarteritis, nodosa
  haemolytic uremic syndrome
  thrombotic thrombocytopenia purport, accelerated HTN
  emboli (thrombotic, atherosclerotic)

Question 23

4 phases of ATN

Answer 23

1. initiating
2. oliguric
3. diuretic
4. recovery