The NEXUS and Canadian C-spine Rules (CCR) are both validated studies which both quote a high sensitivity (over 99%) in detecting clinically significant cervical spine fractures. Both studies primarily used plain films in evaluating their patients.
Sensitivity Specificity
NEXUS study 99.6% 12.6%
CCR Study 99.4% 45.1%
NEXUS
National Emergency X-radiography Utilization Study
A patient’s neck can be clinically cleared safely without radiographic imaging if all five low-risk conditions are met:
- No posterior midline neck pain or tenderness
- No focal neurological deficit
- Normal level of alertness
- No evidence of intoxication
- No clinically apparent, painful distracting injury*
- Long bone fracture,
- A visceral injury requiring surgical consultation,
- A large laceration, degloving injury, or crush injury,
- Large burns, or
- Any other injury producing acute functional impairment
Canadian C-spine Rules (CCR)
The basic approach in this flow-chart is to (1) make sure that the patient meets the same inclusion criteria as in the CCR study. Then (2) determine if there are high-risk findings. If so, go directly to imaging. (3) If there are no high-risk findings, check to see if the patient qualifies as a low-risk candidate where you might be able to clinically clear the c-spine without imaging. (4) If the patient is neither high or low risk, then the patient is moderate risk and requires imaging. Here's a flow chart that I made to help you remember:
(click to enlarge)
Note: Many emergency physicians go straight to CT imaging for patients with neck tenderness and moderate/high risk findings.
I personally rarely use the CCR algorithm because I can rarely remember all of the criteria. NEXUS is nice because of its simplicity. Where the CCR algorithm IS helpful is in clinical clearance of the low-risk patient with neck pain. I've cleared many patients who self-present with a whiplash mechanism (simple rear-end motor vehicle crash) and diffuse neck pain. By NEXUS criteria, you'd have to image them because they have neck tenderness. By CCR criteria, if they can actively rotate their neck 45 degrees left and right, they don't have a clinically significant c-spine injury. No imaging needed.
Feel free to download this card and print on a 4'' x 6'' index card.
I like the mnemonic NSAID for the NEXUS Criteria:
ReplyDeleteNeuro Deficit
Spinal Tenderness (Midline), Stepoff
AMS
Intoxication
Distracting Injury
Awesome mnemonic, Graham. I need a mnemonic to keep all my mnemonics straight!
ReplyDeleteThank you dearly for that flowchart, the CCR is so much easier when presented that way!
ReplyDeleteA daily dilemma in my ED is the rear-end, low-energy motor-vehicle crash patient with neck pain. I'm raised in the fear of missing a c-spine fracture and so have tended to keep the CT machine warm, perhaps too often.
A college of mine working in the radiology told me he had never in his carrier seen a c-spine fracture after that kind of mechanism. He even asked his colleges, some of who have been in practice for 40 years and they hadn't either.
Although I'd never use that for clinical decision I find it interesting that we so dramatically fear that c-spine fracture so seldomly seen...
Michellel...great post. Could you comment on your thoughts about CT vs plain films for imaging? I think current teaching is that plain films are vastly inferior, but may have some utility in your lowest risk patients. What is your take?
ReplyDeleteI really like this. During my wilderness EMT training, we learned about the NEXUS criteria and it's something which we're allowed to do in the field, for obvious reasons. Not all urban medical directors allow this though, so EMS typically backboard just about anyone with a serious MOI, where 'serious' isn't really defined all that well. There have been studies which conclude that EMS backboards people far more than they should and that it can, in some cases, actually cause more problems than it prevents.
ReplyDelete@David: I too have not seen a simple whiplash injury in my 9 years of practice causing a cervical injury... except one case. I would advise towards imaging in patients > 65 years old. I saw a 80 y/o patient with a unifacet joint dislocation in the cervical spine with really very minimal neck pain and tenderness on presentation. By the CCR, this patient would have received imaging (age > 65y).
ReplyDelete@MedSchoolOdyssey: I agree that it's good for prehospital personnel to know the NEXUS criteria, since it helps at least gives you a sense of low vs high suspicion for c-spine injury. Indeed people are backboarded/c-collared excessively but we want a model which has a zero-miss protocol, because missing a c-spine injury is WAY more devastating than missing a minor toe fracture, for instance. Hopefully in the future we can figure out a compromise such that not EVERYONE is getting backboarded/c-collared.
@Corey: The question about CT vs plain films is a complex question which gets asks almost every shift I work.
FACT: Plain films (57%) are less sensitive than CT imaging (98%).
FACT: Plain films subject the patient to much less irradiation than CT.
FACT: Missing a c-spine injury has significant consequences.
So, I would indeed use plain films for the "low risk" patients, as you mention. The problem is in identifying such patients. I factor in the mechanism of injury, patient's age, the degree of neck tenderness, whether s/he is going to CT for other reasons, and my clinical gestalt. The recent literature on CT's lifetime cancer risks to patients has caused medical professionals to complete re-think the use of CT. In the NEJM article by Brenner et al, the lifetime risk for cancer by CT goes significantly down after age 35 y/o. So if I'm on the fence for patients>35, I tend to pick CT over xray.
In the end, it's all about risk stratification and knowing that c-spine plain films may indeed miss quite a few c-spine injuries. Personally, I'm waiting for the day when MRI scanners become as commonplace in ED's as CT scanners.
Any other comments from others?