Acute renal failure classification
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Acute renal failure can complicate a wide spectrum of disorders, and for the purpose of diagnosis and management is divided according to the mechanism that lead to renal compromise. The three categories are pre-renal azotemia (diseases that cause renal hypoperfusion), renal azotemia (diseases directly affecting the renal parenchyma), and post-renal azotemia (diseases affecting the urinary tract causing obstruction). However, the first consensus definition described and the most used definition is known as the RIFLE criteria. The acronym combines a classification of 3 levels of renal dysfunction (Risk, Injury, Failure) with 2 clinical outcomes (Loss, ESRD) to give the RIFLE stages of AKI.
The Levels of Renal Dysfunction
Acute renal failure is usually categorized (as in the flowchart below) according to pre-renal, renal and post-renal causes.
- Compromise in the renal blood flow
- Damage to the kidney itself
- Obstructive causes in the urinary tract
The RIFLE (Risk of renal dysfunction, Injury to the kidney, Failure or Loss of kidney function, and End-stage kidney disease) criteria classifies acute renal failure according to the probable clinical outcomes. The acronym combines a classification of 3 levels of renal dysfunction (Risk, Injury, Failure) with 2 clinical outcomes (Loss, ESRD). This unified classification was proposed to enable a viable comparison in trials of prevention and therapy and to observe clinical outcomes of the defined stages of AKI.
|CLASSIFICATION||GFR CRITERIA||URINE OUTPUT CRITERIA|
|Risk||1.5x increase in SCr or GFR decrease >25%||<0.5 mL/kg/h for 6 hours|
|Injury||2x increase in SCr or GFR decrease >50%||<0.5 mL/kg/h for 12 hours|
|Failure||3x increase in SCr or GFR decrease >75%||<0.3 mL/kg/h for 24 hours or anuria for 12 hours|
|Loss||Complete loss of renal function >4 weeks|
|End Stage Renal Disease||Complete loss of renal function >3 months|
Modified RIFLE Criteria
In 2007, the Acute Kidney Injury Network (AKIN) proposed modified diagnostic criteria based on the RIFLE criteria. AKI was defined as an acute increase in the serum creatinine of ≥ 0.3 mg/dL from baseline within 48 hours, a 50% increase in the serum creatinine concentration, or oliguria <0.5 mL/kg/h for 6 hours (following volume status optimization). The staging criteria retained the Risk, Injury, & Failure stages from the RIFLE criteria, with modifications related to serum creatinine increase.
|CLASSIFICATION||SERUM CREATININE CRITERIA||URINE OUTPUT CRITERIA|
|Stage 1||Increase in SCr ≥0.3 mg/dL or 1.5x to 2x increase from baseline||<0.5 mL/kg/h for 6 hours|
|Stage 2||2x to 3x increase in SCr from baseline||<0.5 mL/kg/h for 12 hours|
|Stage 3||>3x increase in SCr or SCr≥ 4.0 mg/dL with acute increase >0.5 mg/dL||<0.3 mL/kg/h for 24 hours or anuria for 12 hours|
In March 2012, the Kidney Disease – Improving Global Outcomes (KDIGO) Clinical Practice Guidelines for Acute Kidney Injury retained the AKIN staging criteria while implementing modifications to the definition of AKI. AKI was defined as either an increase in serum creatinine by 50% in 7 days, an increase in serum creatinine by 0.3 mg/dL in 2 days, or anuria for more than 12 hours.
- Bellomo R, Ronco C, Kellum JA, Mehta RL, Palevsky P (2004). "Acute renal failure - definition, outcome measures, animal models, fluid therapy and information technology needs: the Second International Consensus Conference of the Acute Dialysis Quality Initiative (ADQI) Group". Critical Care (London, England). 8 (4): R204–12. PMC . PMID 15312219. doi:10.1186/cc2872.
- Lameire N, Van Biesen W, Vanholder R (2005). "Acute renal failure". Lancet. 365 (9457): 417–30. PMID 15680458. doi:10.1016/S0140-6736(05)17831-3.
- Mehta RL, Kellum JA, Shah SV, Molitoris BA, Ronco C, Warnock DG; et al. (2007). "Acute Kidney Injury Network: report of an initiative to improve outcomes in acute kidney injury.". Crit Care. 11 (2): R31. PMC . PMID 17331245. doi:10.1186/cc5713.
- Acute Kidney Injury Work Group (2012). "KDIGO Clinical Practice Guideline for Acute Kidney Injury.". Kidney inter. 6 (2): 1–138.