Emergency
Canadian CT Head Rule (CCHR)
Determines the need for head CT in minor adult head trauma.
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Parameters
Canadian CT Head Rule (CCHR) Result
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Formula
High Risk (Neurosurgical): GCS < 15 at 2h, suspected skull fracture, basilar signs, ≥2 vomiting, age ≥65.
Medium Risk (Brain Injury): Amnesia ≥30m, dangerous mechanism.Clinical Pearls
Safely reduces unnecessary head CT scans and radiation exposure in emergency departments while maintaining near 100% sensitivity for intracranial injuries requiring surgery.
Limitations
Applies ONLY to patients with witnessed loss of consciousness, amnesia, or confusion AND initial GCS 13-15. Does not apply to children (<16 yrs), penetrating trauma, or patients on anticoagulants.