NEXUS Criteria for C-Spine Imaging
NEXUS Criteria
Midline cervical tenderness
Altered level of consciousness
Evidence of intoxication
Focal neurologic deficit
Painful distracting injury
What is the NEXUS Criteria?
The National Emergency X-Radiography Utilization Study (NEXUS) criteria is a clinical decision tool used to determine whether patients with cervical spine trauma require imaging. It was developed to reduce unnecessary radiographic studies while maintaining high sensitivity for clinically significant injuries.
The NEXUS criteria consists of five clinical criteria that, when all absent, indicate a very low probability of clinically significant cervical spine injury.
Clinical Significance
Cervical spine injuries occur in approximately 2-3% of patients with blunt trauma. However, the vast majority of cervical spine radiographs are negative for injury. The NEXUS criteria helps identify patients at very low risk of clinically significant injury, reducing unnecessary imaging, radiation exposure, and healthcare costs.
Studies have shown that proper application of the NEXUS criteria can reduce imaging rates by 12-36% without missing clinically important injuries.
How to Use the Calculator
The NEXUS criteria evaluates five clinical factors:
- Midline cervical tenderness
- Altered level of consciousness
- Evidence of intoxication
- Focal neurologic deficit
- Painful distracting injury
If ALL criteria are absent (all "No" responses), cervical spine imaging is not necessary. If ANY criterion is present (any "Yes" response), imaging is recommended.
Criteria Definitions
Midline Cervical Tenderness
Pain upon palpation of the posterior midline neck from the nuchal ridge to the prominence of the first thoracic vertebra.
Altered Level of Consciousness
GCS <15, disorientation to person, place, time, or events; inability to recall 3 objects at 5 minutes; delayed or inappropriate response to external stimuli.
Evidence of Intoxication
Recent history of intoxication or intoxicating ingestion, evidence of intoxication on physical exam, positive test for drugs or alcohol.
Focal Neurologic Deficit
Any focal neurologic complaint or finding (e.g., numbness, weakness, or sensory loss in an extremity).
Painful Distracting Injury
Any injury that might distract the patient from the pain of a cervical spine injury (e.g., long bone fracture, visceral injury, large laceration, degloving injury, crush injury, large burns).
Limitations
The NEXUS criteria has several limitations:
- It has lower sensitivity in elderly patients (> 65 years)
- Some criteria (e.g., "distracting injury") are subjective and may vary between providers
- It should not be applied to patients who are not alert or have unstable vital signs
- It has not been extensively validated in children under 8 years of age
Clinical judgment should always be used alongside this decision tool. When in doubt, imaging is recommended.
NEXUS vs. Canadian C-Spine Rule
The NEXUS criteria and Canadian C-Spine Rule are both validated clinical decision tools for cervical spine clearance. Studies comparing the two have found:
- The Canadian C-Spine Rule has slightly higher sensitivity (99.4% vs 90.7%)
- The Canadian C-Spine Rule has higher specificity (45.1% vs 36.8%)
- The NEXUS criteria is simpler to apply and remember
- The Canadian C-Spine Rule cannot be used in patients who cannot actively rotate their neck
Both tools are valid options, and the choice between them often depends on institutional preference and provider familiarity.
Evidence and Validation
The NEXUS criteria was derived and validated in a large prospective study of 34,069 patients. It demonstrated a sensitivity of 99.6% for clinically significant cervical spine injuries, with a negative predictive value of 99.9%.
Multiple external validation studies have confirmed its safety and efficacy in various clinical settings, though some studies suggest slightly lower sensitivity than originally reported.
References
- Hoffman JR, Mower WR, Wolfson AB, et al. Validity of a set of clinical criteria to rule out injury to the cervical spine in patients with blunt trauma. N Engl J Med. 2000;343(2):94-99.
- Stiell IG, Clement CM, McKnight RD, et al. The Canadian C-spine rule versus the NEXUS low-risk criteria in patients with trauma. N Engl J Med. 2003;349(26):2510-2518.
- Michaleff ZA, Maher CG, Verhagen AP, Rebbeck T, Lin CW. Accuracy of the Canadian C-spine rule and NEXUS to screen for clinically important cervical spine injury in patients following blunt trauma: a systematic review. CMAJ. 2012;184(16):E867-E876.