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AKIN classification for acute kidney injury

Stages AKI from creatinine change and urine output.

AKIN classification for acute kidney injury
Baseline serum creatinine
mg/dL
Current serum creatinine
AKIN requires the change to occur within 48 hours.
mg/dL
Worst urine output criterion met
Receiving renal replacement therapy
Complete the fields above to see the result.

When to use

  • Diagnosing and staging acute kidney injury within a 48-hour window.

Formula

Stage 1: SCr x1.5-1.99 or rise >=0.3 mg/dL, or UOP <0.5 mL/kg/h >6 h. Stage 2: SCr x2-2.99, or UOP <0.5 >12 h. Stage 3: SCr x>=3, or SCr >=4.0 with acute rise >=0.5, or UOP <0.3 >=24 h / anuria >=12 h, or on RRT. Final stage is the highest criterion met.

Pearls and pitfalls

  • The creatinine change must occur within 48 hours.
  • Any patient started on renal replacement therapy is stage 3 regardless of other values.

References

  1. Mehta RL, et al. Crit Care. 2007;11(2):R31.