Simplified APACHE II Score Calculator Formula

Understand the math behind the simplified apache ii score calculator. Each variable explained with a worked example.

Formulas Used

Simplified APACHE Score

simplified_score = age_points + temp_points + hr_points + gcs_points

Age Points

age_component = age_points

Physiology Points

physiology_component = temp_points + hr_points + gcs_points

Variables

VariableDescriptionDefault
ageAge(years)60
temperature_fTemperature(F)101
heart_rateHeart Rate(bpm)100
gcsGCS Score(/15)14
age_pointsDerived value= age >= 75 ? 6 : (age >= 65 ? 5 : (age >= 55 ? 3 : (age >= 45 ? 2 : 0)))calculated
temp_cDerived value= (temperature_f - 32) * 5 / 9calculated
temp_pointsDerived value= abs(temp_c - 37) >= 4 ? 4 : (abs(temp_c - 37) >= 3 ? 3 : (abs(temp_c - 37) >= 2 ? 2 : (abs(temp_c - 37) >= 1 ? 1 : 0)))calculated
hr_pointsDerived value= abs(heart_rate - 80) >= 70 ? 4 : (abs(heart_rate - 80) >= 45 ? 3 : (abs(heart_rate - 80) >= 30 ? 2 : 0))calculated
gcs_pointsDerived value= 15 - gcscalculated

How It Works

Simplified APACHE II Score

The full APACHE II uses 12 physiologic variables, age, and chronic health status. This simplified version uses the most accessible variables.

Age Points

| Age | Points | |---|---| | <45 | 0 | | 45-54 | 2 | | 55-64 | 3 | | 65-74 | 5 | | 75+ | 6 |

Score Interpretation

Higher scores indicate greater severity. The full APACHE II (0-71) correlates with ICU mortality risk. This simplified version provides a directional estimate.

Worked Example

A 60-year-old ICU patient: temp 101F, HR 100, GCS 14.

age = 60temperature_f = 101heart_rate = 100gcs = 14
  1. 01Age points = 3 (55-64)
  2. 02Temp = 38.3C, deviation = 1.3, points = 1
  3. 03HR deviation from 80 = 20, points = 0
  4. 04GCS points = 15 - 14 = 1
  5. 05Total = 3 + 1 + 0 + 1 = 5