NEXUS Criteria (C-Spine): what it is and how it’s used
The NEXUS (National Emergency X-Radiography Utilization Study) low-risk criteria is a clinical decision instrument designed to help clinicians safely rule out clinically important cervical spine injury after blunt trauma—and therefore avoid unnecessary C-spine imaging in patients who are very low risk. PubMed+1
The 5 NEXUS low-risk criteria
A patient can be considered low probability for C-spine injury only if all five are present (i.e., all are “negative” for risk): PubMed+1
- No posterior midline cervical spine tenderness PubMed+1
- No evidence of intoxication PubMed+1
- Normal level of alertness PubMed+1
- No focal neurologic deficit PubMed+1
- No painful distracting injury PubMed+1
If a patient fails any one of these (i.e., any criterion is positive/abnormal), imaging is generally indicated per local protocol.
What the evidence shows (classic validation)
In the original large multicenter validation study (34,069 blunt trauma patients who underwent C-spine imaging), the NEXUS decision instrument showed:
- Sensitivity ~99.0% for any cervical spine injury and ~99.6% for “clinically significant” injury (as defined in the study) PubMed
- Negative predictive value ~99.8–99.9% PubMed
- Specificity ~12.9%, meaning many patients still trigger imaging PubMed
The study estimated imaging could have been avoided in about 12.6% of evaluated patients by applying the criteria. PubMed
Practical application (in plain language)
Use NEXUS as a screen in appropriate blunt trauma patients:
- If all 5 criteria are met → C-spine injury is very unlikely, and imaging may be avoided (according to your setting’s policy).
- If any criterion is not met → do not clinically clear the C-spine; proceed with imaging and immobilization decisions per local protocol.
Important cautions and limitations
- NEXUS is most appropriate for examinable patients after blunt trauma; it’s not a substitute for resuscitation priorities or for managing unstable patients. PubMed
- “Distracting injury” and “intoxication” require clinical judgment; definitions and examples were discussed in subsequent publications and comparative studies. immediatecaretraining.ie
- Children: NEXUS is widely used, but some pediatric pathways note it has not been fully validated in children—many institutions use pediatric-specific pathways/rules. Johns Hopkins Medicine
- Guidelines vary: In the UK, NICE recommends using the Canadian C-spine rule to assess suspected C-spine injury in adults, rather than NEXUS as the default standard. NICE+1
Clinical note: Always integrate NEXUS with mechanism, exam quality, neuro status, and local imaging pathways (often CT-first in adults where imaging is indicated).
