Canadian CT Head Rule
Which adults with minor head injury need a CT.
Inputs
GCS below 15 at 2 hours after injury
Suspected open or depressed skull fracture
Any sign of basal skull fractureHemotympanum, raccoon eyes, CSF otorrhea or rhinorrhea, Battle sign
Vomiting 2 or more times
Age 65 or older
Amnesia before impact of 30 minutes or more
Dangerous mechanismPedestrian struck, ejected from vehicle, fall from more than 3 feet or 5 stairs
Worked calculation
Your values are highlighted.
- Criteria present
When to use
- Adults with minor head injury (GCS 13–15) and witnessed loss of consciousness, amnesia, or disorientation.
Pearls and pitfalls
- Not for anticoagulated patients, age under 16, seizures, or obvious open skull injury.
- The first five criteria are high risk (neurosurgical intervention); the last two are medium risk (brain injury on CT).
Why use
Highly sensitive for clinically important brain injury with fewer CTs.
Positive if any criterion is present