Extended criteria (experimental). This is the broader ten-condition engine, kept as a secondary area. It shows ICD-10-CM codes and illustrative grouping effects for CDI staff. The primary surface is Before you sign (kidney, measurement only). All extended pages.

Acute kidney injury (KDIGO staging)

Rule aki version 2026.11-1 · condition: Acute kidney injury

Published source

KDIGO Clinical Practice Guideline for Acute Kidney Injury (Kidney Int Suppl 2012;2:19-36) (2012). Recommendations 2.1.1 (definition) and 2.1.2 (staging), Table 2. https://kdigo.org/wp-content/uploads/2016/10/KDIGO-2012-AKI-Guideline-English.pdf · public page checked 2026-11-14

Definition: SCr rise >=0.3 mg/dL within 48 h, or >=1.5x baseline known or presumed within the prior 7 days, or urine output <0.5 mL/kg/h for 6 h. Stage 1: 1.5-1.9x or >=0.3 rise, UO <0.5 for 6-12 h. Stage 2: 2.0-2.9x, UO <0.5 for >=12 h. Stage 3: >=3.0x, or SCr >=4.0 mg/dL, or start of RRT, or UO <0.3 for >=24 h or anuria >=12 h.

Inputs

creat_baseline: Baseline creatinine (mg/dL); most recent pre-admission value within 365 days, else lowest this stay (presumed)
creat_baseline_known: Whether a pre-admission baseline exists
creat_peak: Peak creatinine this stay (mg/dL)
creat_ratio: Peak / baseline
creat_rise_48h: Largest creatinine rise between two values within 48 h (mg/dL)
rrt_started: Dialysis ordered this stay
uo_hours_lt_0_5: Longest run of urine output <0.5 mL/kg/h (hours; 6-hour blocks)
uo_hours_lt_0_3: Longest run of urine output <0.3 mL/kg/h (hours)
anuria_hours: Longest run with no urine output (hours)

Thresholds

t.rise_abs: 0.3
t.ratio_s1: 1.5
t.ratio_s2: 2.0
t.ratio_s3: 3.0
t.scr_s3: 4.0
t.uo_s1_h: 6
t.uo_s2_h: 12
t.uo_s3_h: 24
t.anuria_h: 12

Derived values

Evaluated in order
Name	Expression
meets_definition	`creat_ratio >= t.ratio_s1 or creat_rise_48h >= t.rise_abs or coalesce(uo_hours_lt_0_5 >= t.uo_s1_h, false)`
stage3	`meets_definition and (creat_ratio >= t.ratio_s3 or creat_peak >= t.scr_s3 or rrt_started or coalesce(uo_hours_lt_0_3 >= t.uo_s3_h, false) or coalesce(anuria_hours >= t.anuria_h, false))`
stage2	`creat_ratio >= t.ratio_s2 or coalesce(uo_hours_lt_0_5 >= t.uo_s2_h, false)`
stage	`case(stage3, 3, stage2, 2, meets_definition, 1, 0)`
baseline_independent	`creat_baseline_known or creat_rise_48h >= t.rise_abs or rrt_started`

Outcomes

First true outcome wins; an unknown input makes an outcome unknown
Outcome	When	Status	Supports
aki_staged AKI criteria met, KDIGO stage {stage}	`stage >= 1 and baseline_independent`	supported	N17.9 Acute kidney injury (KDIGO stage {stage}) ICD-10-CM does not code the KDIGO stage; the stage is shown so the clinician can document it.
aki_presumed_baseline AKI criteria met only against a presumed baseline (no pre-admission creatinine on file)	`stage >= 1`	judgement	—
not_met KDIGO creatinine and urine-output criteria not met	`stage == 0`	not_supported	—

ICD-10-CM specificity ladder (FY2026 CC/MCC status as a secondary diagnosis)

N28.9 Renal insufficiency, unspecified (disorder of kidney, unspecified) · non-CC
N17.9 Acute kidney injury (acute kidney failure, unspecified) · CC (refines N28.9)

Query topic: kidney function documentation · prompts for an undocumented diagnosis: yes

Where clinical judgement is required

KDIGO states that clinical judgement is required in choosing the baseline creatinine; a presumed baseline is flagged, not concluded.
Acute tubular necrosis (N17.0) cannot be inferred from creatinine kinetics and is never proposed.

Coding notes

The stage is not part of the ICD-10-CM code (N17.9 for all stages).