🧠 NEXUS Head CT Decision Instrument
UseWhen to use: adults with blunt head trauma within ~24 h in whom CT is being considered.
StrataLow-risk supports deferred CT with return precautions; any criterion supports imaging.
LimitsWhen not to use: penetrating injury, unreliable exam, or when Canadia… · Pitfall: calling facial-only hematoma a scalp hematoma incorrectly — … · High-energy mechanism still warrants clinical judgment.
SourceMower WR, et al. PLoS Med 2017 (NEXUS Head CT DI validation)
This-shift next steps
After scoring: open the scene pack, peer scores, and the matching pathway. Local reference — no HIS write.
Paste the link in Slack, Teams, X, or LinkedIn — the preview image comes from this page’s Open Graph card.
Methodology · worked example, guidelines & full notes
Eight binary criteria.
When to use
When to use: adults with blunt head trauma within ~24 h in whom CT is being considered.
How it works
Low-risk only if ALL absent: age≥65, significant skull fracture signs, scalp hematoma, neurologic deficit, altered alertness, abnormal behavior, coagulopathy, persistent vomiting.
Key points
- Eight binary criteria.
- Any positive → CT.
- Next: Canadian CT Head Rule / PECARN (peds) as locally indicated.
References
- Mower WR, et al. PLoS Med 2017 (NEXUS Head CT DI validation)
- Mower WR, et al. J Trauma 2005 (derivation)
Worked calculation
The values below come from this tool's own example placeholders and are computed server-side with the formula shown on this page, so the arithmetic can be checked quickly. It demonstrates how to substitute values only — it is not clinical advice and not a real case.
| Age ≥ 65 years | No |
|---|---|
| Evidence of significant skull fracture | No |
| Scalp hematoma | No |
| Neurologic deficit | No |
| Altered level of alertness | No |
| Abnormal behavior | No |
| Coagulopathy | No |
| Persistent / recurrent vomiting (>1 episode) | No |
→NEXUS HeadLow-risk — CT may be deferred
- Positive criteria：None
- Rule：Low-risk only if ALL eight absent
| Age ≥ 65 years | Yes |
|---|---|
| Evidence of significant skull fracture | Yes |
| Scalp hematoma | Yes |
| Neurologic deficit | Yes |
| Altered level of alertness | Yes |
| Abnormal behavior | Yes |
| Coagulopathy | Yes |
| Persistent / recurrent vomiting (>1 episode) | Yes |
→NEXUS HeadNot low-risk — CT indicated
- Positive criteria：8
- Rule：Low-risk only if ALL eight absent
Verification & sources · governance
FAQ
Frequently asked questions
- Does NEXUS Head CT Decision Instrument upload patient data? Where is it calculated?
- Calculation runs locally in the browser; inputs and results are not uploaded. For licensed clinicians only; interpret with history, investigations and local protocols — not a diagnosis or prescription.
- How is NEXUS Head CT Decision Instrument calculated in practice? Can you show a worked example?
- Inputs: Age ≥ 65 years No, Evidence of significant skull fracture No, Scalp hematoma No, Neurologic deficit No, Altered level of alertness No, Abnormal behavior No, Coagulopathy No, Persistent / recurrent vomiting (>1 episode) No → Result: NEXUS Head Low-risk — CT may be deferred（Positive criteria: None, Rule: Low-risk only if ALL eight absent） Inputs: Age ≥ 65 years Yes, Evidence of significant skull fracture Yes, Scalp hematoma Yes, Neurologic deficit Yes, Altered level of alertness Yes, Abnormal behavior Yes, Coagulopathy Yes, Persistent / recurrent vomiting (>1 episode) Yes → Result: NEXUS Head Not low-risk — CT indicated（Positive criteria: 8, Rule: Low-risk only if ALL eight absent）