Table 1.

AKIN diagnostic and staging criteria

AKIN StageSCr CriteriaUO Criteria
1SCr increase ≥0.3 mg/dl or SCr ≥1.5- to 2-fold increase from baseline<0.5 ml/kg per hour for >6 h
2SCr >2- to 3-fold increase from baseline<0.5 ml/kg per hour for >12 h
3SCr >3-fold increase from baseline or SCr ≥4 mg/dl (with acute increase of ≥0.5 mg/dl within 24 h) or initiation of RRT (irrespective of stage at time of initiation)<0.3 ml/kg per hour for 24 h or anuria for 12 h
  • A diagnosis is made if at least stage 1 is reached within a 48-hour period; severity is described by the maximum stage reached within a 7-day timeframe. It is assumed that the patient is volume replete (to exclude prerenal azotemia) and that urinary obstruction has been excluded. Details regarding AKIN are available in Mehta et al. (2). AKIN, Acute Kidney Injury Network; SCr, serum creatinine, UO, urine output; RRT, renal replacement therapy.