Rule validated to have >99.8% NPV for clinically important brain injury.
Screening Verdict
CT HEAD NOT REQUIRED
EXCLUSION CRITERIA MET
Clinical Disposition
Absence of all 8 criteria represents a negligible risk for clinically important injury. Discharging without imaging is considered safe.
Validated NEXUS Decision Tool.
Guidelines & Evidence
Clinical Details
Section 1
When to Use
When to Use
Broad screening for any patient with blunt head trauma.
Unlike the Canadian rule, NEXUS II can be applied to patients *without* LOC or amnesia.
Applicable to all ages (validated specifically in infants and children as well).
Useful for standardized ER triage in heterogeneous populations.
Section 2
Formula & Logic
High-Risk Criteria (Any 1 = CT Indicated)
Age: ≥ 65 years.
Skull Fracture: Evidence of significant fracture (open or basal).
Scalp Hematoma: Clinically significant.
Neurologic: Any focal deficit.
Alertness: Altered (GCS ≤ 14).
Behavior: Abnormal behavior noted by clinician or family.
Coagulopathy: Pharmacologic (warfarin, DOAC) or physiologic.
Vomiting: Forceful or recurrent emesis.
Section 3
Pearls/Pitfalls
Coagulopathy Coverage
NEXUS II is one of the few rules that explicitly lists coagulopathy as a primary trigger for CT. In the era of widespread DOAC and antiplatelet use, this provides a critical safety net that other "minor head injury" rules sometimes lack.
Section 4
Evidence Appraisal
Primary Reference
Developing a decision instrument to guide computed tomographic imaging of blunt head injury patients
