On the Shoulders of Giants
The NEXUS criteria can be used to determine which patients do not need c-spine x-rays. Since this was published, we have shifted to predominantly CT imaging, which is more sensitive. Also, we have learned that NEXUS is not as sensitive in elderly patients.
Why does this matter?
Plain c-spine x-rays require a significant dose of radiation to get all the views. C-spine CT requires even more. If a patient is low-risk based on clinical criteria, the c-spine may be cleared without any radiographs. This saves time and money. Plus it can be applied in settings without ready access to x-ray or in the field.
How many NEXUS have you cleared?
This was a multi-center prospective observational cohort with over 34,000 patients with blunt trauma who were to undergo c-spine x-ray. The 5 NEXUS criteria, if all negative, were 99% sensitive (99.6% sensitive for clinically significant c-spine injury) and had a NPV of 99.8% (99.9% for clinically significant injury). Specificity was low at 12.6%, PPV 2.7%, which has been one of the major complaints about NEXUS.
The NEXUS criteria are:
- no midline cervical tenderness
- no focal neurologic deficit
- normal alertness
- no intoxication
- no painful, distracting injury
I use the NEXUS criteria in practice. Some prefer the Canadian c-spine rule, which I find harder to recall. But that's why we have MDCalc, right!
Methodology - Selective cervical spine radiography in blunt trauma: methodology of the National Emergency X-Radiography Utilization Study (NEXUS). Ann Emerg Med. 1998 Oct;32(4):461-9.
Actual study - Validity of a set of clinical criteria to rule out injury to the cervical spine in patients with blunt trauma. National Emergency X-Radiography Utilization Study Group. N Engl J Med. 2000 Jul 13;343(2):94-9.