EBQ:NEXUS cervical trauma rule

Complete Journal Club Article
Hoffman JR, Mower WR, Wolfson AB, Todd KH, Zucker MI.. "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. 2001. 343(2):94-9.
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Clinical Question

Can a clinical decision rule be used to evaluate the need for radiography of the cervical spine after blunt trauma?

Conclusion

The NEXUS C-spine rule is a highly sensitive decision rule used to guide the use of cervical-spine radiography in patients with blunt trauma.

Major Points

Five Main Questions:

  1. Is a focal neurologic deficit present?
  2. Is there midline spinal tenderness?
  3. Does the patient have altered mental status?
  4. Is the patient intoxicated?
  5. Does the patient have an apparent distracting injury?
  • If the answer is "yes" to any of these questions, imaging in recommended.
  • The rule had 99% sensitivity and 12.9% specificity for identifying 810 patients with cervical spine injury.
  • The Canadian C-spine Rule is also useful for risk stratifying patients into low risk groups that can foregoe cervical spine radiographs. While the NEXUS criteria uses 5 items, the Canadian cervical spine rule uses 3 high risk, 5 low risk and pain free rotation of the neck to stratify trauma patients.

Study Design

  • Multicenter, prospective, observational study of ED patients with blunt trauma for whom cervical spine imaging is ordered.[1]
  • Completed in 21 centers across the United States (community and university hospitals)
  • Each center had a physician who served as liaison to the study (received 1 hour training), and a designated radiologist who ensured correct data collection
  • Physicians allowed to order images of patients at their own discretion
    • Imaging was an X-ray series of 3 views of C-spine (cross table lateral, AP, open mouth odontoid) unless CT/MRI performed
  • All physicians submitted prospective data on all patients before imaging completed, unless patient was clinically unstable

Population

Patient Demographics

Mean age: 37 (range 1-101 years) Sex: 58.7% male

Inclusion Criteria

  • Patients with blunt trauma who underwent radiography of the C-spine in participating ED
  • Decision wheher to order radiography was made at discretion of the treating physician, according to the criteria he or she ordinarily used

Exclusion Criteria

  • Patients with penetrating trauma
  • Those who underwent cervical-spine imaging for any other reason, unrelated to trauma

Interventions

The NEXUS study was an observational trial

Outcomes

n=34,069 patient evaluated y imaging of cervical spine

Primary Outcome

818 (2.4%) had radiographically documented cervical-spine injury
578 (1.7%) had clinically significant cervical-spine injury

  • Not clinically significant cervical-spine injuries
    • Spinous-process fracture
    • Simple wedge-compression fracture with < 25% loss of vertebral-body heigt
    • Isolated avulsion without associated ligamentous injury
    • Type I odontoid fracture
    • End-plate fracture
    • Osteophyte fracture, not including corner fracture or teardrop fracture
    • Injury to trabecular bone
    • Tranverse-process fracture
Any Cervical Spine Injury Value (95% CI)
Sensitivity 99.0 (98.0-99.6)
Specificity 12.9 (12.8-13.0)
Negative Predictive Value 99.8 (99.6-100)
Positive Predictive Value 2.7 (2.6-2.8)
Clinically Significant Cervical Spine Injury Value (95% CI)
Sensitivity 99.6 (98.6-100)
Specificity 12.9 (12.8-13.0)
Negative Predictive Value 99.9 (99.8-100)
Positive Predictive Value 1.9 (1.8-2.0)

Secondary Outcomes

  • Good-to-excellent interobserver reliability (kappa, 0.58-0.86)
  • Excellent interobserver agreement (kappa, 0.73)

Subgroup analysis

Criticisms & Further Discussion

  • Decision rule requires clinical gestault
    • Individual criteria such as "distracting injury" not explicitly defined
  • The resultant decrease in ordering of radiographs was small than the reduction of almost 30% in previous NEXUS study [2]
    • May reflect an influence of the previous study on participating institutions
  • At the time some considered a five views c-spine series to be the standard and thus a false sense of security could be found using less views as was done in this study (cross-table lateral, anteroposterior, open-mouth, and right and left obliques)
  • Prospective evaluation of NEXUS in the setting of CT scanning rather than plain films did identify a 0.9% miss rate[3]
  • The Canadian cervical spine rule in a single study has been shown to be more sensitive than NEXUS (99.4 percent vs. 90.7 percent, P<0.001) and more specific (45.1 percent vs. 36.8 percent, P<0.001) for injury, and its may result in lower radiography rates[4]

See Also

External Links

Funding

Grant from the Agency for Healthcare Research and Quality

References

  1. Hoffman JR, Wolfson AB, Todd K, Mower WR. 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.
  2. Hoffman JR, SChringer DL, Mower WR, Luo JS, Zucker M. Low-risk criteria for cervical-spine radiography in blunt trauma: a prospective study. Ann Emerg Med 1992;12:1454-60.
  3. Duane TM. et al. National Emergency X-Radiography Utilization Study criteria is inadequate to rule out fracture after significant blunt trauma compared with computed tomography. J Trauma. 2011 Apr;70(4):829-31
  4. Stiell, Ian et al. The Canadian C-Spine Rule versus the NEXUS Low-Risk Criteria in Patients with Trauma. N Engl J Med 2003; 349:2510-2518

Authors:

Ross Donaldson