Double the score if acute renal failure (use clinical judgment for acute kidney injury)
Hematocrit (%)
White Blood Cell Count (x10³/μL)
Glasgow Coma Scale
Age (years)
Chronic Health Points
For severe organ insufficiency or immunocompromised state
Type of Admission
Acute Renal Failure
Note: "acute renal failure" was not defined in the original study. Use clinical judgment to determine whether patient has acute kidney injury.
APACHE II Score — — 0% estimated nonoperative mortality
0/16 answered · tap options to update (0–71)
Instructions
The APACHE II score is calculated using acute physiological measurements, age, and chronic health status. Clinicians should collect vital parameters such as temperature, mean arterial pressure, heart rate, respiratory rate, oxygenation status, arterial pH, sodium, potassium, creatinine, hematocrit, white blood cell count, and Glasgow Coma Scale (GCS). Each variable is scored based on severity, with higher deviations from normal values receiving higher points. Additional points are assigned for age and severe chronic health conditions. The total score reflects illness severity and is used to predict hospital mortality in critically ill patients.
Overview
When to use
Why use
Evidences
Interpretation
APACHE II Score
Estimated Mortality Risk
0–4
~4%
5–9
~8%
10–14
~15%
15–19
~25%
20–24
~40%
25–29
~55%
30–34
~73%
≥35
~85%
APACHE II (Acute Physiology and Chronic Health Evaluation II) was introduced in 1985 as a general ICU severity-of-disease system that sums points from 12 physiologic variables (worst values in first 24 h), age, and chronic health status to yield a 0–71 score strongly correlated with hospital mortality across 5,815 ICU admissions in 13 hospitals https://pubmed.ncbi.nlm.nih.gov/3928249/
In a trauma cohort analysis, APACHE II predicted mortality with AUROC 0.77 and outperformed ISS and TRISS, with somewhat higher discrimination in penetrating trauma (AUROC 0.81) than blunt trauma (0.76)
Serial/dynamic reassessment can improve prognostication; in one study, the day‑3 APACHE II had higher AUROC (0.666 on day 3 vs ~0.58 on days 1–2), with further gains by days 7–28, suggesting early re-evaluation refines risk estimates
Comparative studies show APACHE II has similar discrimination to SAPS II in some cohorts and often better discrimination than SOFA for mortality prediction when used as a single baseline score
Intercenter evaluations highlight the need for standardized data collection; scoring inaccuracies and case-mix differences can affect calibration and reliability, reinforcing the importance of training and local validation when using APACHE II for benchmarking
The APACHE II scoring system is one of the most widely used critical care severity indices in intensive care units (ICUs). It was first introduced in 1985 as an update to the original APACHE model to improve prediction accuracy and simplify use in clinical practice. The score integrates a combination of physiological variables, patient age, and chronic health conditions into a single index that quantifies severity of illness.
The score ranges from 0 to 71, with higher values indicating greater disease severity and higher predicted mortality risk. It is not disease-specific but rather designed as a general prognostic tool for critically ill patients with a wide variety of conditions, including sepsis, respiratory failure, trauma, and multi-organ dysfunction.
APACHE II is most commonly applied within the first 24 hours of ICU admission, using the worst values for each parameter recorded during that period. This ensures that the model reflects the most severe physiological derangements early in the ICU stay.
Overview
When to use
Why use
Evidences
Interpretation
APACHE II Score
Estimated Mortality Risk
0–4
~4%
5–9
~8%
10–14
~15%
15–19
~25%
20–24
~40%
25–29
~55%
30–34
~73%
≥35
~85%
APACHE II (Acute Physiology and Chronic Health Evaluation II) was introduced in 1985 as a general ICU severity-of-disease system that sums points from 12 physiologic variables (worst values in first 24 h), age, and chronic health status to yield a 0–71 score strongly correlated with hospital mortality across 5,815 ICU admissions in 13 hospitals https://pubmed.ncbi.nlm.nih.gov/3928249/
In a trauma cohort analysis, APACHE II predicted mortality with AUROC 0.77 and outperformed ISS and TRISS, with somewhat higher discrimination in penetrating trauma (AUROC 0.81) than blunt trauma (0.76)
Serial/dynamic reassessment can improve prognostication; in one study, the day‑3 APACHE II had higher AUROC (0.666 on day 3 vs ~0.58 on days 1–2), with further gains by days 7–28, suggesting early re-evaluation refines risk estimates
Comparative studies show APACHE II has similar discrimination to SAPS II in some cohorts and often better discrimination than SOFA for mortality prediction when used as a single baseline score
Intercenter evaluations highlight the need for standardized data collection; scoring inaccuracies and case-mix differences can affect calibration and reliability, reinforcing the importance of training and local validation when using APACHE II for benchmarking
