====== 🧠 NEXUS-II Criteria for Head CT in Blunt Head Trauma ======

<wrap lo>**Purpose:**</wrap>  
To identify patients with **blunt head trauma (GCS ≥13)** who are at **low risk for clinically significant intracranial injury (ICI)** and **may not require head CT**.

<wrap info>
**A Head CT is recommended if ANY of the following are present:**
  - Evidence of significant skull fracture (e.g., basilar signs, palpable step-off)
  - Scalp hematoma
  - Neurological deficit
  - Altered level of alertness
  - Abnormal behavior
  - Coagulopathy
  - Persistent vomiting
  - Age ≥ 65 years
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<wrap hi>**Inclusion Criteria:**</wrap>
  * Blunt head trauma  
  * GCS ≥ 13  
  * Age ≥ 1 year  
  * Stable vital signs  

<wrap important>**Performance:**</wrap>  
  * Sensitivity: **~98–99%** (excellent for ruling out significant injury)  
  * Specificity: **Low** (many unnecessary scans avoided only if used judiciously)  

📊 Comparison with Other Head CT Rules

^ Rule         ^ GCS Range ^ Focus                      ^ Sensitivity ^ Specificity ^
| NEXUS-II     | ≥13       | Safety net, easy to apply  | Very high   | Low         |
| CCHR         | 13–15     | High-risk neurosurgical signs | High     | Moderate    |
| NOC          | 15        | Symptom-based              | Very high   | Low         |



<wrap tip>
**Clinical Tip:**  
NEXUS-II is a **broad and highly sensitive rule** that helps **rule out the need for CT** in patients with **no red flags**. Especially valuable in busy EDs or resource-limited settings.
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