APACHE II Score (ICU)

APACHE II Score Calculator

Acute Physiology and Chronic Health Evaluation for ICU patients

Calculator

About APACHE II

Patient Information

Age (years)

Chronic Health Status None Chronic disease (mild) Chronic disease (severe) or immunocompromised

Physiological Parameters

Temperature (°C)

Mean Arterial Pressure (mmHg)

Heart Rate (bpm)

Respiratory Rate (breaths/min)

PaO₂ (mmHg) ?Arterial oxygen partial pressure

FiO₂ (%) ?Fraction of inspired oxygen (enter as percentage, e.g. 21 for room air)

Arterial pH

Serum Sodium (mEq/L)

Serum Potassium (mEq/L)

Serum Creatinine (mg/dL)

Hematocrit (%)

White Blood Count (×10³/mm³)

Glasgow Coma Score (GCS)

If patient is intubated/unable to speak, estimate verbal score based on eye/motor responses

APACHE II Results

0

Predicted Hospital Mortality Rate: 0%

Low Risk

Score Breakdown

About APACHE II

The APACHE II (Acute Physiology and Chronic Health Evaluation II) is a severity-of-disease classification system that is applied within 24 hours of admission of a patient to an intensive care unit.

Components of APACHE II

The score is calculated based on:

• 12 physiological variables (worst values in first 24 hours)
• Age points
• Chronic health points

Score Interpretation

Higher scores correlate with more severe disease and higher risk of hospital mortality:

• 0-4: Low risk (~4% mortality)
• 5-9: Mild risk (~8% mortality)
• 10-14: Moderate risk (~15% mortality)
• 15-19: High risk (~25% mortality)
• 20-24: Severe risk (~40% mortality)
• 25-29: Critical risk (~55% mortality)
• 30+: Extremely critical risk (~75% mortality)

Limitations

While APACHE II is widely used, it has some limitations:

• Doesn't account for diagnosis or treatment
• Less accurate for individual patient predictions
• Should be used in conjunction with clinical judgment