Acute Kidney Injury - CIS

Question 1

3 classifications of acute kidney injury and their associated BUN:Cr ratios

Answer 1

Pre-renal = BUN:Cr >20:1

Intrarenal (intrinsic) = BUN:Cr <20:1

Post-Renal = normal BUN:Cr (~15-20)

Question 2

3 major types of intrinsic AKI’s

Answer 2

Tubular necrosis

Interstitial nephritis

Acute glomerulonephritis

Question 3

2 major causes of tubular necrosis

Answer 3

Ischemia (50%)

Toxins (35%)

Question 4

KDIGO is the most used criteria for staging AKI, what are the determinants?

Answer 4

Serum creatinine
Urine output
Initiation of RRT (dialysis)

Question 5

Cockcroft-Gault calculation for creatinine clearance

Answer 5

[(140-age)(weight in kg)(0.85 if female)] / (72 x PCr)

Question 6

Anion gap calculation

Answer 6

(Na) - (Cl + HCO3)

Question 7

Which is associated with acute kidney injury: hypernatremia or hyponatremia?

Answer 7

Hypernatremia

Question 8

Hypovolemia, nephrosis, cirrhosis, CHF are associated with what sodium levels?

Answer 8

Hyponatremia

Question 9

What potassium status would you expect in a patient with vomiting or diarrhea?

Answer 9

Hyperkalemic

Question 10

T/F: Hypokalemia is usually associated with renal disease with hormonal implications

Answer 10

True

Question 11

Hypotension and sepsis are common causes of what type of AKI?

Answer 11

Acute tubular necrosis

Question 12

Other causes of acute tubular necrosis

Answer 12

Renal ischemia
Nephrotoxins
Major surgery
Hypoperfusion
Endogenous toxins
Burns

Question 13

What type of AKI is characterized by a decline in renal function secondary to renal lesion, aka an inflammatory reaction within the renal interstitium?

Answer 13

Acute interstitial nephritis

Question 14

Which AKI is characterized by a broad range of clinical findings including hematuria and proteinuria, as well as renal insufficiency, possible hypertension, edema, and hypercoagulability?

Answer 14

Acute glomerulonephritis

Question 15

Calculating fractional excretion of sodium

Answer 15

(SCr x UNa)/(SNa x UCr) x100%

A FENa<1% suggests pre-renal disease while between 1-2% suggests intrinsic disease (only applies in patients with marked reduction in GFR)