CAISS EXAM 2026 Updated Version
QUESTIONS AND ANSWERS | Complete Test
Bank with Rationales | Grade A+ Assured | Pass
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SECTION 1: AIS FUNDAMENTALS AND SCORING PRINCIPLES
Questions 1-20
Question 1 The Abbreviated Injury Scale (AIS) severity score for a "critical" injury is:
A. 3
B. 4
C. 5 [CORRECT]
D. 6
Correct Answer: C
Rationale: The AIS severity scale is defined as follows: 1 = Minor, 2 = Moderate, 3 = Serious, 4
= Severe, 5 = Critical, 6 = Maximal (currently untreatable). A critical injury (AIS 5) represents
injuries with a high probability of death that are potentially survivable with immediate and
optimal medical intervention (e.g., ruptured aorta with contained hematoma, severe liver
laceration with active hemorrhage).
Why distractors are incorrect:
• A (3): This represents "serious" injuries, not critical.
• B (4): This represents "severe" injuries—serious but with better prognosis than critical.
• D (6): This represents "maximal" or unsurvivable injuries, which is a distinct category
beyond critical.
Question 2 An AIS score of 6 indicates:
A. Minor injury
B. Moderate injury
,C. Critical injury
D. Maximal injury (currently untreatable) [CORRECT]
Correct Answer: D
Rationale: AIS 6 is reserved for maximal injuries that are currently untreatable and virtually
invariably fatal. Examples include massive brainstem destruction, complete transection of the
thoracic aorta with free rupture, or liver avulsion. These injuries represent the upper limit of the
scale and automatically result in an ISS of 75.
Why distractors are incorrect:
• A and B: These represent low-severity injuries at the opposite end of the scale.
• C: Critical injuries (AIS 5) are potentially survivable with optimal care, whereas AIS 6
injuries are considered unsurvivable regardless of intervention.
Question 3 The AIS code is a 7-digit number. The first digit represents:
A. Severity
B. Body region [CORRECT]
C. Type of anatomic structure
D. Specific anatomic structure
Correct Answer: B
Rationale: The 7-digit AIS code structure follows this format: Digit 1 = Body Region (1=Head,
2=Face, 3=Neck, 4=Thorax, 5=Abdomen, 6=Spine, 7=Upper Extremity, 8=Lower Extremity,
9=External); Digit 2 = Type of Anatomic Structure; Digits 3-4 = Specific Anatomic Structure;
Digit 5 = Level; Digits 6-7 = Severity. The body region digit is always first to allow immediate
categorization of the injury location.
Why distractors are incorrect:
• A: Severity is represented by the last two digits (6-7), not the first.
• C: Type of structure is the second digit.
• D: Specific structure is digits 3-4.
Question 4 When a patient has multiple injuries to the same body region, the AIS coding rule for
ISS calculation is to:
A. Code all injuries separately
B. Code only the most severe injury in that region [CORRECT]
,C. Code the average severity of all injuries
D. Code only the first injury documented
Correct Answer: B
Rationale: For ISS calculation, the fundamental rule is to use only the highest severity injury
from each of the six body regions. This prevents overestimation of severity from multiple
injuries in one region. However, for complete trauma registry documentation, all injuries should
be coded separately. The distinction between registry coding (document all) and ISS calculation
(use maximum per region) is a common source of confusion.
Why distractors are incorrect:
• A: While all injuries should be documented in the registry, ISS calculation specifically
uses only the most severe per region.
• C: Averaging is never used in AIS or ISS methodology.
• D: The order of documentation has no bearing on severity assessment; the most severe
injury must be identified regardless of when it was documented.
Question 5 A patient has bilateral pulmonary contusions. According to AIS 2025 coding
conventions, how should this be coded?
A. As a single injury code with bilateral designation [CORRECT]
B. As two separate injury codes (left and right)
C. As only the more severe side
D. With a bilateral modifier that doubles the severity
Correct Answer: A
Rationale: AIS 2025 allows for coding bilateral injuries as a single entry with laterality specified
where appropriate, or using specific bilateral codes when available in the dictionary. The severity
assigned reflects the combined physiological impact of the bilateral injury. Coding as two
separate injuries (Option B) would inappropriately allow both to be counted in ISS calculation,
potentially from the same body region, which violates AIS principles.
Why distractors are incorrect:
• B: Coding separately would create two injuries from the same body region for ISS
calculation, which is prohibited.
• C: Ignoring the less severe side underrepresents the total injury burden.
• D: There is no mechanism in AIS for "doubling" severity; bilateral injuries are assigned
appropriate severity based on combined impact.
, Question 6 Which of the following AIS 2025 body region codes is CORRECT?
A. 1 = Face, 2 = Head
B. 3 = Neck [CORRECT]
C. 5 = Thorax
D. 8 = Upper Extremity
Correct Answer: B
Rationale: The standard AIS body region codes are: 1 = Head, 2 = Face, 3 = Neck, 4 = Thorax, 5
= Abdomen, 6 = Spine, 7 = Upper Extremity, 8 = Lower Extremity, 9 = External and Other. Code
3 correctly represents the Neck region, which includes cervical spine, cervical spinal cord, and
neck structures (vessels, airway, esophagus).
Why distractors are incorrect:
• A: Reverses head (1) and face (2).
• C: Thorax is code 4, not 5 (abdomen).
• D: Upper extremity is code 7; lower extremity is code 8.
Question 7 The AIS severity scale is:
A. A prognostic scale predicting outcome
B. An anatomical injury severity scale [CORRECT]
C. A physiological scoring system
D. A measure of functional impairment
Correct Answer: B
Rationale: AIS is fundamentally an anatomical injury severity scale. It describes the severity of
tissue damage based on anatomical structures affected, not physiological response, prognosis, or
functional outcome. While higher AIS scores correlate with worse outcomes, the scale itself
measures anatomical disruption. This distinction is crucial for proper application.
Why distractors are incorrect:
• A: While correlated with outcome, AIS does not predict prognosis directly.
• C: Physiological systems include GCS, RTS, or APACHE; AIS is anatomical.
• D: Functional measures are captured by other instruments (GOS, FIM), not AIS.
QUESTIONS AND ANSWERS | Complete Test
Bank with Rationales | Grade A+ Assured | Pass
Guaranteed - A+ Graded
SECTION 1: AIS FUNDAMENTALS AND SCORING PRINCIPLES
Questions 1-20
Question 1 The Abbreviated Injury Scale (AIS) severity score for a "critical" injury is:
A. 3
B. 4
C. 5 [CORRECT]
D. 6
Correct Answer: C
Rationale: The AIS severity scale is defined as follows: 1 = Minor, 2 = Moderate, 3 = Serious, 4
= Severe, 5 = Critical, 6 = Maximal (currently untreatable). A critical injury (AIS 5) represents
injuries with a high probability of death that are potentially survivable with immediate and
optimal medical intervention (e.g., ruptured aorta with contained hematoma, severe liver
laceration with active hemorrhage).
Why distractors are incorrect:
• A (3): This represents "serious" injuries, not critical.
• B (4): This represents "severe" injuries—serious but with better prognosis than critical.
• D (6): This represents "maximal" or unsurvivable injuries, which is a distinct category
beyond critical.
Question 2 An AIS score of 6 indicates:
A. Minor injury
B. Moderate injury
,C. Critical injury
D. Maximal injury (currently untreatable) [CORRECT]
Correct Answer: D
Rationale: AIS 6 is reserved for maximal injuries that are currently untreatable and virtually
invariably fatal. Examples include massive brainstem destruction, complete transection of the
thoracic aorta with free rupture, or liver avulsion. These injuries represent the upper limit of the
scale and automatically result in an ISS of 75.
Why distractors are incorrect:
• A and B: These represent low-severity injuries at the opposite end of the scale.
• C: Critical injuries (AIS 5) are potentially survivable with optimal care, whereas AIS 6
injuries are considered unsurvivable regardless of intervention.
Question 3 The AIS code is a 7-digit number. The first digit represents:
A. Severity
B. Body region [CORRECT]
C. Type of anatomic structure
D. Specific anatomic structure
Correct Answer: B
Rationale: The 7-digit AIS code structure follows this format: Digit 1 = Body Region (1=Head,
2=Face, 3=Neck, 4=Thorax, 5=Abdomen, 6=Spine, 7=Upper Extremity, 8=Lower Extremity,
9=External); Digit 2 = Type of Anatomic Structure; Digits 3-4 = Specific Anatomic Structure;
Digit 5 = Level; Digits 6-7 = Severity. The body region digit is always first to allow immediate
categorization of the injury location.
Why distractors are incorrect:
• A: Severity is represented by the last two digits (6-7), not the first.
• C: Type of structure is the second digit.
• D: Specific structure is digits 3-4.
Question 4 When a patient has multiple injuries to the same body region, the AIS coding rule for
ISS calculation is to:
A. Code all injuries separately
B. Code only the most severe injury in that region [CORRECT]
,C. Code the average severity of all injuries
D. Code only the first injury documented
Correct Answer: B
Rationale: For ISS calculation, the fundamental rule is to use only the highest severity injury
from each of the six body regions. This prevents overestimation of severity from multiple
injuries in one region. However, for complete trauma registry documentation, all injuries should
be coded separately. The distinction between registry coding (document all) and ISS calculation
(use maximum per region) is a common source of confusion.
Why distractors are incorrect:
• A: While all injuries should be documented in the registry, ISS calculation specifically
uses only the most severe per region.
• C: Averaging is never used in AIS or ISS methodology.
• D: The order of documentation has no bearing on severity assessment; the most severe
injury must be identified regardless of when it was documented.
Question 5 A patient has bilateral pulmonary contusions. According to AIS 2025 coding
conventions, how should this be coded?
A. As a single injury code with bilateral designation [CORRECT]
B. As two separate injury codes (left and right)
C. As only the more severe side
D. With a bilateral modifier that doubles the severity
Correct Answer: A
Rationale: AIS 2025 allows for coding bilateral injuries as a single entry with laterality specified
where appropriate, or using specific bilateral codes when available in the dictionary. The severity
assigned reflects the combined physiological impact of the bilateral injury. Coding as two
separate injuries (Option B) would inappropriately allow both to be counted in ISS calculation,
potentially from the same body region, which violates AIS principles.
Why distractors are incorrect:
• B: Coding separately would create two injuries from the same body region for ISS
calculation, which is prohibited.
• C: Ignoring the less severe side underrepresents the total injury burden.
• D: There is no mechanism in AIS for "doubling" severity; bilateral injuries are assigned
appropriate severity based on combined impact.
, Question 6 Which of the following AIS 2025 body region codes is CORRECT?
A. 1 = Face, 2 = Head
B. 3 = Neck [CORRECT]
C. 5 = Thorax
D. 8 = Upper Extremity
Correct Answer: B
Rationale: The standard AIS body region codes are: 1 = Head, 2 = Face, 3 = Neck, 4 = Thorax, 5
= Abdomen, 6 = Spine, 7 = Upper Extremity, 8 = Lower Extremity, 9 = External and Other. Code
3 correctly represents the Neck region, which includes cervical spine, cervical spinal cord, and
neck structures (vessels, airway, esophagus).
Why distractors are incorrect:
• A: Reverses head (1) and face (2).
• C: Thorax is code 4, not 5 (abdomen).
• D: Upper extremity is code 7; lower extremity is code 8.
Question 7 The AIS severity scale is:
A. A prognostic scale predicting outcome
B. An anatomical injury severity scale [CORRECT]
C. A physiological scoring system
D. A measure of functional impairment
Correct Answer: B
Rationale: AIS is fundamentally an anatomical injury severity scale. It describes the severity of
tissue damage based on anatomical structures affected, not physiological response, prognosis, or
functional outcome. While higher AIS scores correlate with worse outcomes, the scale itself
measures anatomical disruption. This distinction is crucial for proper application.
Why distractors are incorrect:
• A: While correlated with outcome, AIS does not predict prognosis directly.
• C: Physiological systems include GCS, RTS, or APACHE; AIS is anatomical.
• D: Functional measures are captured by other instruments (GOS, FIM), not AIS.
