KDIGO AKI staging

Q: What is AKI stage 1 by KDIGO?

Creatinine 1.5–1.9 × baseline or a rise of ≥ 26.5 µmol/L (0.3 mg/dL) within 48 hours, or urine output < 0.5 mL/kg/h for 6–12 hours.

Q: What counts as KDIGO stage 3?

Creatinine ≥ 3 × baseline, or ≥ 353.6 µmol/L (4.0 mg/dL) once AKI criteria are met, or start of renal replacement therapy, or urine output < 0.3 mL/kg/h for 24 hours or anuria for 12 hours.

Q: What if I don't know the baseline creatinine?

KDIGO allows a presumed baseline; a repeat value after recovery often clarifies it. Without any baseline, only the 48-hour absolute rise and urine output criteria can be applied with confidence.

Acute kidney injury stage from creatinine rise, urine output and dialysis

KDIGO 2012 AKI guideline

Sources last checked: 2026-10-13

KDIGO AKI staging

Acute kidney injury stage from creatinine rise, urine output and dialysis

Creatinine unit

Baseline serum creatinine (µmol/L or mg/dL)Lowest value in the last 3 months, or a presumed baseline if none is known.Current (peak) serum creatinine (µmol/L or mg/dL)

Time over which the rise occurred

Urine output

Renal replacement therapy started

Fill in every field to see the result.

Adults only here: the paediatric stage-3 criterion (eGFR < 35 mL/min/1.73 m²) is not included. Clinical judgement decides whether the chosen baseline is valid.

Source: Kidney Disease: Improving Global Outcomes (KDIGO) Acute Kidney Injury Work Group. KDIGO Clinical Practice Guideline for Acute Kidney Injury. Kidney Int Suppl 2012;2(1):1-138 (recommendations 2.1.1–2.1.2, table 2).Open

Interpretation

No AKI by these criteria	Creatinine and urine output do not meet the KDIGO definition. A slower rise (> 7 days) may still be acute kidney disease (AKD).
AKI stage 1	KDIGO 2012 lists for stage 1: identifying and treating the cause, reviewing nephrotoxic drugs and dosing, monitoring creatinine and urine output.
AKI stage 2	KDIGO 2012 lists the stage-1 measures plus review of drug dosing and of whether RRT may become necessary.
AKI stage 3	Highest risk of death and need for RRT; KDIGO 2012 lists nephrology / critical-care involvement for this stage.

What is the KDIGO AKI staging?

KDIGO staging classifies acute kidney injury into stages 1–3 by the rise in serum creatinine from baseline, the duration of reduced urine output and the start of renal replacement therapy. The 2012 KDIGO guideline merged the earlier RIFLE and AKIN criteria into one definition used internationally.

When to use it

Hospitalised patients with a rising creatinine or falling urine output
Post-operative and intensive-care monitoring
Audit and electronic AKI alerts

When not to use it

Chronic, slowly progressive creatinine rise (> 7 days) — this pattern fits CKD or acute kidney disease
Children, without the paediatric eGFR criterion

How it is calculated

Stage 1: creatinine 1.5–1.9 × baseline (within 7 days) or rise ≥ 26.5 µmol/L (≥ 0.3 mg/dL) within 48 h; or urine < 0.5 mL/kg/h for 6–12 h Stage 2: creatinine 2.0–2.9 × baseline; or urine < 0.5 mL/kg/h for ≥ 12 h Stage 3: creatinine ≥ 3.0 × baseline, or ≥ 353.6 µmol/L (≥ 4.0 mg/dL) once AKI criteria are met, or start of renal replacement therapy; or urine < 0.3 mL/kg/h for ≥ 24 h or anuria ≥ 12 h The highest stage reached by any criterion applies.

Clinical pearls and limitations

Adults only here: the paediatric stage-3 criterion (eGFR < 35 mL/min/1.73 m²) is not included. Clinical judgement decides whether the chosen baseline is valid.
AKI = rise ≥ 26.5 µmol/L (0.3 mg/dL) within 48 h, or ≥ 1.5 × baseline within 7 days, or urine < 0.5 mL/kg/h for 6 h.
Stage by whichever criterion gives the highest stage.
Creatinine ≥ 353.6 µmol/L (4.0 mg/dL) means stage 3 only after an AKI-defining rise has occurred.
Choosing the baseline matters: use the lowest recent value, or a presumed baseline when none exists.

Frequently asked questions

What is AKI stage 1 by KDIGO?

Creatinine 1.5–1.9 × baseline or a rise of ≥ 26.5 µmol/L (0.3 mg/dL) within 48 hours, or urine output < 0.5 mL/kg/h for 6–12 hours.

What counts as KDIGO stage 3?

Creatinine ≥ 3 × baseline, or ≥ 353.6 µmol/L (4.0 mg/dL) once AKI criteria are met, or start of renal replacement therapy, or urine output < 0.3 mL/kg/h for 24 hours or anuria for 12 hours.

What if I don't know the baseline creatinine?

KDIGO allows a presumed baseline; a repeat value after recovery often clarifies it. Without any baseline, only the 48-hour absolute rise and urine output criteria can be applied with confidence.

Evidence and guidelines

Primary source: Kidney Disease: Improving Global Outcomes (KDIGO) Acute Kidney Injury Work Group. KDIGO Clinical Practice Guideline for Acute Kidney Injury. Kidney Int Suppl 2012;2(1):1-138 (recommendations 2.1.1–2.1.2, table 2).

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