A P A C H E I I
Low severity, good prognosis
Why This Health Metric Matters
Why: This calculation helps assess important health parameters for clinical and personal wellness tracking.
How: Enter your values above and the calculator will apply validated formulas to compute your results.
- ●Evidence-based calculations
- ●Used in clinical settings worldwide
- ●Regular monitoring recommended
🏥 Sample ICU Scenarios
💓 Vital Signs
🫁 Oxygenation
🩸 Arterial Blood Gas
🧪 Chemistry
🔬 Hematology
🧠 Neurologic
👤 Age & Chronic Health
APACHE II Score
Score Components
Visual Analysis
📊 APACHE II Score Gauge
📈 Score Components
🎯 Physiology Variable Profile
☠️ Mortality by Score Range
Individual Variable Scores
| Variable | Value | Points |
|---|---|---|
| Temperature | 37.0°C | 0 |
| MAP | 80 mmHg | 0 |
| Heart Rate | 80 bpm | 0 |
| Respiratory Rate | 16/min | 0 |
| Oxygenation | PaO2 80 | 0 |
| Arterial pH | 7.40 | 0 |
| Sodium | 140 mEq/L | 0 |
| Potassium | 4.0 mEq/L | 0 |
| Creatinine | 1.0 mg/dL | 0 |
| Hematocrit | 40% | 0 |
| WBC | 10 x1000/µL | 0 |
| GCS Points | 15 - 15 | 0 |
Step-by-Step Calculation
The APACHE II score uses worst values in the first 24 hours of ICU admission.
Temperature (37°C): 0 points
Mean Arterial Pressure (80 mmHg): 0 points
Heart Rate (80 bpm): 0 points
Respiratory Rate (16/min): 0 points
Oxygenation (PaO2 80 mmHg): 0 points
Arterial pH (7.4): 0 points
Sodium (140 mEq/L): 0 points
Potassium (4 mEq/L): 0 points
Creatinine (1 mg/dL): 0 points
Hematocrit (40%): 0 points
WBC (10 x1000/µL): 0 points
Glasgow Coma Score (15 - 15): 0 points
Total Acute Physiology Score: 0 points
Age (50 years): 2 points
No severe organ insufficiency: 0 points
Total = APS (0) + Age (2) + Chronic Health (0) = 2
Risk Category: Low Risk
Predicted Hospital Mortality: ~6%
APACHE II Mortality Reference
| Score Range | Risk Level | Mortality Rate | Description |
|---|---|---|---|
| 0-4 | Low Risk | ~4% | Low severity, good prognosis |
| 5-9 | Low-Moderate | ~8% | Mild illness severity |
| 10-14 | Moderate | ~15% | Moderate illness severity |
| 15-19 | Moderate-High | ~25% | Significant illness severity |
| 20-24 | High | ~40% | High severity, guarded prognosis |
| 25-29 | Very High | ~55% | Very high severity |
| 30-34 | Critical | ~75% | Critical illness |
| ≥35 | Extreme | >85% | Extremely critical |
⚠️For informational purposes only — not medical advice. Consult a healthcare professional before acting on results.
🏥 Health Facts
— WHO
— CDC
📋 What is the APACHE II Score?
The APACHE II (Acute Physiology and Chronic Health Evaluation II) score is a severity-of-disease classification system developed in 1985 by Knaus et al. It is one of the most widely used and validated ICU scoring systems worldwide for predicting hospital mortality in critically ill patients.
The score combines 12 routine physiologic measurements (Acute Physiology Score), patient age, and chronic health conditions into a single numerical score ranging from 0 to 71, with higher scores indicating greater severity of illness and higher predicted mortality.
Score Components
- Acute Physiology Score (APS): 12 physiologic variables (0-60 points)
- Age Points: 0-6 points based on age brackets
- Chronic Health Points: 0-5 points for severe organ insufficiency
🔧 How to Calculate APACHE II
- Collect Data: Use worst values from first 24 hours of ICU admission
- Calculate APS: Score each of 12 physiologic variables (0-4 points each)
- Add Age Points: 0-6 points based on patient age
- Add Chronic Health Points: 2-5 points for severe organ insufficiency
- Sum Total: APS + Age Points + Chronic Health Points
12 Physiologic Variables
⏰ When to Use APACHE II
Appropriate Use
- • ICU admission risk stratification
- • Clinical research and trials
- • Quality benchmarking between ICUs
- • Resource allocation planning
- • Prognostic discussions with families
Limitations
- • Based on 1979-1982 patient data
- • Does not account for specific diagnoses
- • May underestimate mortality in some groups
- • Not validated for all ICU populations
- • Newer versions (APACHE III, IV) available
📐 APACHE II Formula
APACHE II = APS + Age Points + Chronic Health Points
APS = Sum of 12 physiologic variable scores (0-4 points each)
Maximum Score = 60 + 6 + 5 = 71 points
Age Scoring
- ≤44 years: 0 points
- 45-54 years: 2 points
- 55-64 years: 3 points
- 65-74 years: 5 points
- ≥75 years: 6 points