New Orleans Criteria
Computed tomography is required for patients with minor head injury with any 1
of the following findings. The criteria apply only to patients who also have a Glasgow
Coma Scale score of 15.
3. Older than 60 years
4. Drug or alcohol intoxication
5. Persistent anterograde amnesia (deficits in short-term memory)
6. Visible trauma above the clavicle
Canadian CT Head Rule*
Computed tomography is only required for patients with minor head injury with
any 1 of the following findings: Patients with minor head injury who present with
a Glasgow Coma Scale score of 13 to 15 after witnessed loss of consciousness, amnesia,
High Risk for Neurosurgical Intervention
1. Glasgow Coma Scale score lower than 15 at 2 hours after injury
2. Suspected open or depressed skull fracture
3. Any sign of basal skull fracture†
4. Two or more episodes of vomiting
5. 65 years or older
Medium Risk for Brain Injury Detection by Computed Tomographic Imaging
6. Amnesia before impact of 30 or more minutes
7. Dangerous mechanism‡
*The rule is not applicable if the patient did not experience a trauma, has a Glasgow Coma
Scale score lower than 13, is younger than 16 years, is taking warfarin or has a bleeding disorder,
or has an obvious open skull fracture.
†Signs of of basal skull fracture include hemotympanum, racoon eyes, cerebrospinal fluid,
otorrhea or rhinorrhea, Battle’s sign.
‡Dangerous mechanism is a pedestrian struck by a motor vehicle, an occupant ejected from
a motor vehicle, or a fall from an elevation of 3 or more feet or 5 stairs.
Mnemonic: "Canadians get (GCS) sloppy (Skull fx) and (Age>65) vomit"
Canadian CT Head Rule
Stiell et al. The Canadian CT Head Rule for patients with minor head injury . The Lancet , Volume 357, Issue 9266 , Pages 1391 - 1396
The 3121 patients had the following characteristics: mean age 38·7 years); GCS scores of 13 (3·5%), 14 (16·7%), 15 (79·8%);
8% had clinically important brain injury; and 1% required neurological intervention.
Five high-risk factors:
failure to reach GCS of 15 within 2 h
suspected open skull fracture
any sign of basal skull fracture
vomiting ≥2 episodes
age ≥65 years
Two additional medium-risk factors:
amnesia before impact >30 min
dangerous mechanism of injury
The high-risk factors were 100% sensitive (95% CI 92–100%) for predicting need for neurological intervention, and would require only 32% of patients to undergo CT. The medium-risk factors were 98·4% sensitive (95% CI 96–99%) and 49·6% specific for predicting clinically important brain injury, and would require only 54% of patients to undergo CT.
-Stiell et al. The Canadian CT Head Rule for patients with minor head injury . The Lancet , Volume 357, Issue 9266 , Pages 1391 - 1396
The NOC and the CCHR both had 100% sensitivity but the CCHR was more specific (76.3% vs 12.1 %, P<.001) for predicting need for neurosurgical intervention. For clinically important brain injury, the CCHR and the NOC had similar sensitivity (100% vs 100%; 95% confidence interval [Cl], 96%-100%) but the CCHR was more specific (50.6% vs 12.7%, P<.001), and would result in lower CT rates (52.1 % vs 88.0%, P<.001).
-Stiell, et al. Comparison of the Canadian CT Head Rule and the New Orleans Criteria in patients with minor head injury