ACUTE KIDNEY INJURY Flashcards
What does AKI stand for?
Acute Kidney Injury
Define AKI.
Sudden decrease in kidney function over hours to days.
What is the preferred term for acute renal failure?
AKI
What is oliguria?
Reduced urine volume (<0.5 mL/kg/h in children, <20 mL/h in adults, <400-500 mL/day in adults)
What is anuria?
Urine output <100 mL/day
What does the RIFLE criteria stand for?
Risk, Injury, Failure, Loss, End-stage
What is the AKIN criteria?
Added absolute increase in serum creatinine (≥0.3 mg/dL over 48 hours)
What does the KDIGO criteria combine?
RIFLE and AKIN criteria
How is AKI staged?
Based on serum creatinine increase or oliguria duration
What is the incidence of AKI in hospitalized patients?
5-10%
What is the incidence of AKI in critically ill patients?
35-60%
What percentage of AKI cases are due to prerenal azotemia?
50-70%
What is obstructive nephropathy’s contribution to AKI cases?
5% of cases
What are the causes of intrinsic AKI?
Includes ATN, AIN, glomerulonephritis, vascular diseases, crystal deposition
What characterizes prerenal azotemia?
Diminished kidney perfusion, reversible with restoration of perfusion
What is ATN?
Most common intrinsic AKI; caused by ischemia or nephrotoxins
What are the mechanisms of ATN?
Intratubular obstruction, tubular back leak, vasoconstriction, microvascular injury
What is AIN?
Immunologically mediated interstitial nephritis, often drug-induced
What laboratory findings indicate prerenal azotemia?
High BUN:creatinine ratio, low urine sodium, high urine osmolality
What laboratory findings indicate ATN?
Low BUN:creatinine ratio, high urine sodium, low urine osmolality
What is the fractional excretion of sodium (FENa) in prerenal azotemia?
<1%
What is the FENa in ATN?
> 2%
What is the fractional excretion of urea (FEurea) in prerenal azotemia?
<35%
What is the FEurea in ATN?
> 50%
