CAISS Head and Neck Injuries 5 — Questions and Answers
Question 1: Which of the following best describes why AIS 6 is not used frequently in clinical data registries compared to AIS 5?
- AIS 6 requires a separate coding manual
- AIS 6 is reserved for injuries with 0% survival regardless of care, which rarely meet strict criteria (Correct answer)
- AIS 6 applies only to pediatric patients
- AIS 6 was removed in the 2015 revision
Correct answer: AIS 6 is reserved for injuries with 0% survival regardless of care, which rarely meet strict criteria
AIS 6 requires that the injury be fundamentally unsurvivable regardless of optimal treatment, a high bar that few injuries strictly meet.
Question 2: A trauma patient has a fracture of the odontoid process (C2) with anterior subluxation but no cord signal change on MRI. What is the AIS severity?
- AIS 2
- AIS 3
- AIS 4 (Correct answer)
- AIS 5
Correct answer: AIS 4
An odontoid fracture with subluxation but no cord injury codes to AIS 4 because the instability poses a significant threat to the spinal cord.
Question 3: In the MAIS (Maximum AIS) calculation for a crash victim with head and neck injuries, how is MAIS determined?
- Average of all AIS scores
- Sum of all AIS scores
- Highest single AIS score across all body regions (Correct answer)
- Highest AIS score within the head region only
Correct answer: Highest single AIS score across all body regions
MAIS is the single highest AIS severity score across all coded injuries, regardless of body region.
Question 4: A patient is diagnosed with a basilar skull fracture with hemotympanum and raccoon eyes but no neurological deficits. What AIS level applies?
- AIS 2
- AIS 3 (Correct answer)
- AIS 4
- AIS 5
Correct answer: AIS 3
A basilar skull fracture with clinical signs but without neurological compromise is coded AIS 3 (Serious).
Question 5: Which of the following neck vascular injuries would typically receive the highest AIS severity?
- Minor external jugular vein laceration
- Internal jugular vein laceration
- Vertebral artery thrombosis
- Carotid artery transection (Correct answer)
Correct answer: Carotid artery transection
Carotid artery transection is an immediately life-threatening injury and receives the highest AIS severity among neck vascular injuries.
Question 6: When coding closed head injury in a child under 2 years who cannot participate in GCS assessment, the AIS coder should:
- Default to AIS 1
- Use the pediatric GCS modification and available imaging findings (Correct answer)
- Skip head coding entirely
- Assign AIS 6 by default
Correct answer: Use the pediatric GCS modification and available imaging findings
The pediatric GCS modification with CT/MRI findings guides AIS coding in preverbal children who cannot reliably perform standard GCS tasks.
Question 7: In AIS, which additional data element is captured alongside the AIS severity code to enable ISS calculation?
- Mechanism of injury code
- Body region number (1–9) (Correct answer)
- Anatomical structure digit
- Treatment code
Correct answer: Body region number (1–9)
The body region number (1–9) paired with the AIS severity is essential for ISS calculation, which squares the three highest AIS scores from different body regions.
CAISS Head and Neck Injuries 5
Which of the following best describes why AIS 6 is not used frequently in clinical data registries compared to AIS 5?