The RIFLE (risk, injury, failure, loss, end-stage) classification can be used to describe the severity of renal injury.
Acute renal injury should be both:
(1) abrupt (within 1 to 7 days)
(2) sustained (lasting more than 24 hours)
Acute renal injury - based on the worse of glomerular filtration rate (GFR) and urine output criteria
(1) risk (R)
(2) injury (I)
(3) failure (F)
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Serum Creatinine (GFR criteria)
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Class
|
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1.5 to 1.99 times baseline
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risk
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2 to 2.99 times baseline
|
injury
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>= 3 times baseline
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failure
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>= 4 mg/dL with acute rise > 0.5 mg/dL
|
failure
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where:
• GFR is calculated from serum creatinine using the MDRD equation.
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Urine Output
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Class
|
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< 0.5 mL per kg per hour for 6+ hours
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risk
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< 0.5 mL per kg per hour for 12+ hours
|
injury
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< 0.3 mL per kg per hour for 24+ hours
|
failure
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anuria for 12+ hours
|
failure
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Chronic renal injury:
(4) loss (L): complete loss of renal function > 4 weeks (persistent ARF)
(5) end-stage (E): end stage renal disease for > 3 months
