Injury Severity Score is based on Abbreviated Injury Scale and is used in the assessment of injury in adults an children both. It along with pediatric trauma score are quite reliable in predicting injury measure in children.
Abbreviated Injury Scale is an anatomical scoring system where injuries are ranked on a scale of 1 to 6, with 1 being minor, 5 severe, and 6 a nonsurvivable injury.
The objective of the Abbreviated Injury Scale is to gauge threat to life associated with an injury and is not meant to represent a comprehensive measure of severity.
Detailed scoring is done as follows
- Minor – 1
- Moderate – 2
- Serious – 3
- Severe – 4
- Critical – 5
- Unsurvivable – 6
Injury Severity Score
The Injury Severity Score is an anatomical scoring system that provides an overall score for patients with multiple injuries to measure the injury.
Each injury is assigned an abbreviated injury score and is allocated to one of six body regions
- Head
- Face
- Chest
- Abdomen
- Extremities including Pelvis
- External
Out of these 6 areas, 3 most severely injured body regions are chosen and have their score squared and added together to produce the ISS score.
An example of the ISS calculation is shown below
| Region | Injury Description | AIS | Square(Top Three) |
| Head & Neck | Cerebral Contusion | 3 | 9 |
| Face | No Injury | 0 | – |
| Chest | Flail Chest | 4 | 16 |
| Abdomen | Minor Contusion of LiverComplex Rupture Spleen | 25 | 25 |
| Extremity | Fractured femur | 3 | – |
| External | No injury | 0 | – |
|
Total Injury Severity Score = 9+16+25=50 |
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Maximum possible injury severity score is 75 and minimum 0.
If an injury is assigned an Abbreviated Injury Score of 6 (unsurvivable injury), the Injury Severity Score is automatically assigned to 75.
Injury Severity Score correlates linearly with mortality, morbidity, hospital stay and other measures of severity.
