Clinical decision rules for head CT in trauma

Canadian Rule

Inclusion Criteria

• Not applicable for:
  • Non-trauma
  • GCS<13
  • Age <16
  • Bleeding disorder or on anti-coagulation
  • Obvious open skull fracture

Rule

• Head CT required if ANY of the following are present:

1. Age >65 years
2. Vomiting >2 times
3. Suspected open or depressed skull fracture
4. Signs suggesting basal skull fracture:
   1. Hemotympanum
   2. Racoon eyes
   3. CSF otorrhea or rhinorrhea
   4. Battle's sign
5. GCS <15 at 2 hours post injury
6. Amnesia before impact >30min
7. Dangerous mechanism
   1. Pedestrian struck by vehicle
   2. Ejection from motor vehicle
   3. Fall from elevation >3 feet or 5 stairs

New Orleans Rule

Inclusion Criteria

• Age >18
• GCS 25
• Blunt head trauma occurring within previous 24hr causing LOC, amnesia, or disorientation

Rule

• Head CT required if ANY of the following are present:

1. Headache
2. Vomiting
3. Age >60yr
4. Drug or alcohol intoxication
5. Persistent anterograde amnesia (deficits in short-term memory)
6. Visible trauma above the clavicles
7. Seizure
8. Vomiting >2 times
9. GCS <15 at 2 hours post injury

Decision Rule Performance

1. Sensitivity
   1. Canadian: 99%
   2. New Orleans rule: 99%
   3. Nexus II: 97%
2. Specificity
   1. Canadian: 47%
   2. New Orleans: 33%
   3. Nexus II: 47%

Source

1. Annals of Emerg Med 2009; 53, 2:180-188.
2. http://www.ohri.ca/emerg/cdr/cthead.html

• Haydel MJ, Preston CA, Mills TJ, Luber S, Blaudeau E, DeBlieux PM. Indications for computed tomography in patients with minor head injury. N Engl J Med. 2000;343:100–5.
• Papa L et al. Performance of the Canadian CT Head Rule and the New Orleans Criteria for predicting any traumatic intracranial injury on computed tomography in a United States level I trauma center. Acad Emerg Med 2012 Jan; 19:2