What are the NEXUS (National Emergency X-Radiography Utilization Study) criteria for determining the need for cervical spine imaging in trauma patients?

NEXUS Criteria for Cervical Spine Imaging in Trauma Patients

The NEXUS (National Emergency X-Radiography Utilization Study) criteria is a validated clinical decision tool that identifies patients with a very low probability of cervical spine injury, allowing clinicians to safely avoid unnecessary cervical spine imaging in trauma patients who meet all criteria. 1

The Five NEXUS Criteria

Cervical spine imaging is indicated if ANY of the following criteria are present:

1. Midline cervical spine tenderness
2. Altered level of consciousness
3. Evidence of intoxication
4. Focal neurologic deficit
5. Distracting injury

If ALL criteria are ABSENT (i.e., patient has none of these findings), the patient is considered NEXUS negative and cervical spine imaging can be safely avoided.

Clinical Performance and Validation

The NEXUS criteria demonstrate:

• Sensitivity: 99.0% for detecting clinically significant cervical spine injuries 2
• Negative predictive value: 99.8% 2
• Specificity: 12.9% 2

This high sensitivity and negative predictive value means that when properly applied, the NEXUS criteria can reliably identify patients who do not need cervical spine imaging, potentially reducing unnecessary radiography by approximately 12.6% 2.

Important Considerations and Limitations

1. Age considerations:

   • The NEXUS criteria are less sensitive in older adults (≥65 years) with a sensitivity of only 94.8% 3
   • Consider liberal imaging in elderly patients regardless of NEXUS criteria 3, 4

2. Pediatric application:

   • NEXUS has been validated in pediatric populations with 100% sensitivity 5
   • However, caution is advised in very young children (under 2 years) due to limited study data 5

3. Assessment challenges:

   • "Altered level of consciousness" refers to GCS <15 or any alteration in alertness
   • "Distracting injury" is subjective but includes any injury painful enough to distract from cervical spine pain

Comparison with Canadian C-Spine Rule

While this question focuses on NEXUS, it's worth noting that the Canadian C-Spine Rule is an alternative decision tool with:

• Similar sensitivity (100%) 6
• Higher specificity (allowing for greater reduction in imaging) 6
• More complex algorithm requiring assessment of range of motion in select patients 6

Clinical Application Algorithm

1. Assess all five NEXUS criteria systematically
2. If ANY criterion is present → Obtain cervical spine imaging
3. If ALL criteria are absent → No imaging needed (99.8% NPV)
4. Special consideration for elderly patients (≥65) → Consider imaging regardless of NEXUS criteria

The NEXUS criteria provide a simple, reliable approach to determine the need for cervical spine imaging in trauma patients, but clinical judgment remains important, particularly in high-risk populations like the elderly.