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emergency-medicine neurology neurosurgery

CT Head Rules (NICE/Canadian)

Combines NICE CG176 and Canadian CT Head Rule criteria for immediate CT head in adults with head injury. Reduces unnecessary CT while identifying neurosurgically significant injuries.

Used in: Head Injury

Score interpretation

Low risk — CT not immediately required

→ Observation 4 hours; safe discharge with head injury advice leaflet if GCS 15 and no ongoing symptoms; return if: worsening headache, vomiting, confusion, seizure, limb weakness; GP follow-up if persistent symptoms

Moderate risk — consider CT head

→ CT head within 1 hour of risk factor identification; neurosurgery referral criteria: GCS <13, contusion, midline shift; monitor in ED; reassess neurological status every 30 min

High risk — immediate CT head

→ CT head immediately (<1 hour); neurosurgical referral; anticoagulation reversal (idarucizumab for dabigatran, andexanet alfa for Xa inhibitors, vitamin K + PCC for warfarin); HDU monitoring; neurosurgical consult if: haematoma >1cm, midline shift >5mm, posterior fossa lesion

Interpretation bands for the CT Head Rules. Apply clinical judgement and local guidance.

References

Related

Curated clinical cross-links plus same-class fallbacks.

📚 MRCEM Revision

Featured in these MRCEM clinical pathways

The CT Head Rules is covered in detail — with RCEM/NICE evidence base, indications and pitfalls — in the following exam-focused pathways on our sister siteReviseMRCEM.

MRCEM Primary / Intermediate / OSCE candidates: each pathway includes exam-style questions, RCEM/NICE citations, and FAQ summaries.

Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.