NEXUS C-Spine Criteria Calculator
NEXUS criteria for cervical spine imaging after blunt trauma in stable adults.
What it does
NEXUS stands for the National Emergency X-Radiography Utilization Study. Its criteria help decide whether a stable adult with blunt trauma needs cervical spine imaging.
The five findings are midline cervical tenderness, focal neurologic deficit, altered level of alertness, intoxication, and a painful distracting injury. Any one finding makes NEXUS positive and means the rule cannot clear the cervical spine.
NEXUS is negative only when all five are absent. In the right patient, a negative NEXUS supports clearing the cervical spine without imaging. The rule was derived for blunt trauma and relies on a reliable examination.
The defaults have no findings, so NEXUS is negative and the tool states that imaging is not required by the rule. Clinical judgment still applies, especially if the mechanism or examination is concerning.
How to use
- Confirm that the injury is blunt and the patient is stable.
- Check for midline cervical spine tenderness.
- Perform a neurologic examination for a focal deficit.
- Assess alertness, intoxication, and whether another painful injury could distract from neck symptoms.
- Press Calculate to see the number of findings and the NEXUS result.
- Use the result within the local trauma pathway; do not apply it to penetrating trauma.
Formula
- Midline tenderness
- Tenderness along the posterior midline of the cervical spine.
- Neurologic deficit
- A focal motor or sensory deficit.
- Alertness
- Altered level of alertness.
- Intoxication
- Clinical evidence of alcohol or drug intoxication.
- Distracting injury
- A painful injury that could mask cervical symptoms.
Count the findings. NEXUS is negative only at a count of zero. Any positive finding means the rule cannot clear the cervical spine. NEXUS applies to blunt trauma with a reliable examination and is not validated for penetrating trauma, young children, or patients who cannot be examined reliably.
Worked example
Example: no NEXUS findings after blunt trauma
Defaults: no midline tenderness, no focal deficit, normal alertness, no intoxication, and no distracting injury.
- Midline cervical tenderness: absent.
- Focal neurologic deficit: absent.
- Altered alertness: absent.
- Intoxication: absent.
- Painful distracting injury: absent.
- All five findings are absent, so NEXUS is negative.
- The tool states that cervical spine imaging is not required by NEXUS.
Reference table
| Finding | NEXUS positive when |
|---|---|
| Midline cervical tenderness | Present |
| Focal neurologic deficit | Present |
| Altered level of alertness | Present |
| Intoxication | Present |
| Painful distracting injury | Present |
Limits
- NEXUS applies to blunt trauma, not penetrating trauma.
- It requires a reliable examination and a patient who can report symptoms.
- It is not validated for young children or for patients with altered mental status.
- A negative NEXUS does not override concerning mechanism, worsening symptoms, or clinician concern.
Common mistakes
- Applying NEXUS to penetrating neck or spine trauma.
- Calling NEXUS negative when one finding is present.
- Using the rule in a patient who cannot be examined reliably.
- Ignoring a distracting injury that could hide cervical symptoms.
- Treating a negative NEXUS as permission to skip reassessment.
Try it yourself
Quick checks. Answers sit tucked under each question.
A patient has midline cervical tenderness only. What is the NEXUS result?
NEXUS positive. Midline tenderness is one finding, so the rule cannot clear the cervical spine.
A patient has a painful distracting injury only. What is the NEXUS result?
NEXUS positive. A distracting injury is one of the five findings.
A patient has no findings on NEXUS. What is the result?
NEXUS negative. Imaging is not required by the rule in a reliable examination.
Questions
What does NEXUS stand for?
National Emergency X-Radiography Utilization Study. It is a clinical decision rule for cervical spine imaging.
When is NEXUS negative?
Only when all five findings are absent: no midline tenderness, no focal deficit, normal alertness, no intoxication, and no distracting injury.
Does a negative NEXUS mean no injury?
No. It means the rule does not require imaging in a reliable examination. Clinical judgment and follow-up still matter.
Can NEXUS be used in children?
The rule was derived in adults. Children need a pediatric clearance pathway or clinician judgment.
What if the patient is intoxicated?
Intoxication is a positive finding, so NEXUS cannot clear the cervical spine. Reassess when the patient is reliable or use imaging per protocol.
Is NEXUS the same as the Canadian C-spine rule?
No. They are separate decision rules. The Canadian rule uses different criteria and may be preferred in some settings.