Over 30 different definitions of<unk>  have been used in the literature since it was first described, which prompted the need for a uniform definition.  In 2002, The Acute Dialysis Quality Initiative (ADQI) proposed the first consensus definition known as the RIFLE criteria.  The acronym combines a classification of 3 levels of renal dysfunction (Risk,<unk> , 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<unk> .
In 2007, the<unk>  Network <unk> N) proposed a modified diagnostic criteria based on the RIFLE criteria. The initiative separated the definition and staging into 2 separate entities previously combined in the RIFLE criteria. This made the definition more clinically applicable.<unk>  was defined as either one of the following:
An increase in serum creatinine by 0.3 mg/dL in 48 hours
An increase in serum creatinine by more than 50% of baseline or 1.5 times baseline occuring in the past 7 days
A decrease in urine volume <0.5 mL/kg/h for 6 hours
In March 2012, the<unk>  Disease Improving Global Outcomes (KDIGO) Clinical Practice Guidelines for<unk>  retained the<unk> N definition while implementing modifications to the staging criteria of<unk> .
Acute kidney injury
Acute kidney failure
Acute renal failure
Acute liver failure
Papillorenal syndrome
Nephritic syndrome
Cardiorenal syndrome
Tumor lysis syndrome