CAISS Injury Severity Scoring 2 — Questions and Answers
Question 1: The Injury Severity Score (ISS) is derived from which scoring system?
- Glasgow Coma Scale
- Abbreviated Injury Scale (Correct answer)
- Revised Trauma Score
- APACHE II
Correct answer: Abbreviated Injury Scale
The ISS is calculated using the three highest AIS scores from different body regions.
Question 2: What is the maximum possible Injury Severity Score?
- 50
- 64
- 75 (Correct answer)
- 100
Correct answer: 75
The maximum ISS is 75, achieved when all three contributing AIS scores are 5 (5²+5²+5²=75).
Question 3: A patient has AIS scores of 3, 4, and 2 in three different body regions. What is the ISS?
- 9
- 16
- 25
- 29 (Correct answer)
Correct answer: 29
ISS = 3² + 4² + 2² = 9 + 16 + 4 = 29.
Question 4: Which ISS threshold is most commonly used to define 'major trauma'?
- 9
- 15 (Correct answer)
- 24
- 50
Correct answer: 15
An ISS ≥ 15 is the most widely accepted threshold for defining major or severe trauma.
Question 5: An AIS severity code of 6 indicates which outcome?
- Critical, uncertain survival
- Maximum injury, currently survivable
- Unsurvivable injury (Correct answer)
- Severe injury requiring surgery
Correct answer: Unsurvivable injury
AIS 6 represents an unsurvivable injury, such as decapitation or destruction of a vital structure.
Question 6: When a patient receives an AIS 6 in any body region, the ISS is automatically set to:
- 36
- 64
- 75 (Correct answer)
- 100
Correct answer: 75
An AIS 6 injury is considered unsurvivable and automatically assigns the maximum ISS of 75.
Question 7: The New Injury Severity Score (NISS) differs from ISS in that it:
- Uses six body regions instead of nine
- Takes the three highest AIS scores regardless of body region (Correct answer)
- Excludes head injuries from calculation
- Applies only to penetrating trauma
Correct answer: Takes the three highest AIS scores regardless of body region
NISS uses the three highest AIS scores from any body region, allowing multiple injuries from the same region to contribute.
CAISS Injury Severity Scoring 2
The Injury Severity Score (ISS) is derived from which scoring system?