27 y/o M calls you asking whether or not he should go to the ED to get a CT scan. He just fell off his motorcycle on train tracks and hit his un-helmeted head. He might have lost consciousness for a minute or so, but has since returned to his baseline. Other than a small abrasion at the site of impact, he states everything is all right.
Which clinical decision rules do you use ?
This is minor head injury. There are two commonly used and validated studies to employ in deciding whether or not a CT scan is necessary. Both the New Orleans Criteria and the Canadian CT Head Rules have been prospectively validated in predicting clinically significant head injury. When the two rules were compared head to head, the New Orleans Criteria was slightly more sensitive but had a much lower specificity for identifying clinically significant brain injury. Essentially, this means it sent more patients to CT who ended up not having much of anything, but in doing so missed very few clinically important brain injuries. Peruse the criteria below; if they meet just one of them, send them to CT.
Canadian CT Head Rule
Only applies to pts w/ GCS of 13-15, witnessed LOC, or amnesia to the head injury event. Those w/ minor head injuries w/out one of these factors were excluded.
The mnemonic I was taught for the Canadian CT Head Rule was “Canadians Get Smashed And Vomit All Morning” Scan your patient if
GCS < 13 two hours after injury
Skull fracture suspicion or signs (i.e. basilar skull fracture signs)
Age > 65
Vomit > 2 times
Amnesia > 30 min before injury
Mechanism severe (i.e. pedestrian struck, fall > 3 feet, thrown from motor vehicle)
New Orleans Criteria
The New Orleans Criteria doesn’t have a fun mnemonic to remember it by, but it’s easiest to remember by thinking of it as an ultra-sensitive Canadian CT Head Rule. Think in terms of this rule is looking for the tiniest signs of head injury so I can send them to CT. For example, one of the criterion is simply “headache.” I think of it as a “Canadian CT Head Plus.”
Grouped in order from most sensitive to least (in my opinion)…
Visible trauma above clavicles
Drug or EtOH intoxication
Age > 60
So, the aforementioned patient could definitely be sent to CT via the New Orleans Criteria given that he had a headache. However, the Canadian CT Head Rule would not be so quick to act. The only one he meets is the mechanism and even then it’s a soft call as he wasn’t really ejected from a motor vehicle.