PECARN traumatic brain injury algorithm

The PECARN (Pediatric Emergency Care Applied Research Network) traumatic brain injury algorithm is a clinical decision rule that aims to identify children at very low risk of clinically important traumatic brain injury (ci-TBI) 1. This validated pediatric algorithm predicts likelihood of the above and guides the decision to examine with CT 1,2.

Clinically important TBI was defined where there was any of:

  • death from traumatic brain injury
  • neurosurgery
  • intubation for >24 hours for traumatic brain injury
  • hospital admission of ≥2 nights associated with traumatic brain injury on CT


The following is an example of criteria enabling ci-TBI to be safely ruled out without CT head:

  • age <2 years
    • normal mental status
    • normal behavior per routine caregiver
    • no loss of consciousness (LOC)
    • no severe mechanism of injury
    • no non-frontal scalp hematoma
    • no evidence of skull fracture
  • age ≥2 to 18 years
    • normal mental status
    • no LOC
    • no severe mechanism of injury
    • no vomiting
    • no severe headache
    • no signs of basilar skull fracture


Blunt head trauma is common in children and a common reason for presentation to an emergency department. Head CT involves radiation exposure and the risk of fatal radiation-related malignancy increases with younger age at CT 3. The PECARN flow diagram flags assessment features that increase the risk of ci-TBI and weighs them against the risk of radiation exposure. Therefore, it is useful in avoiding unnecessary radiation exposure in younger patients, where it is safe to do so, and identifying those at risk that requires further investigation.

In PECARN, altered mental status was defined as GCS 14 or agitation, somnolence, repetitive questioning, or slow response to verbal communication.

Severe mechanism of injuries included:

  • motor vehicle crash with patient ejection
  • death of another passenger, or rollover
  • pedestrian or bicyclist without helmet struck by a motorised vehicle
  • falls   
    • more than 1.5 m (5 feet) for patients aged 2 years and older
    • more than 0.9 m (3 feet) for those younger than 2 years
  • head struck by a high-impact object

The algorithm was created from patients presenting to an emergency department within 24 hours of the trauma and with blunt trauma only.

Excluded criteria included:

  • penetrating trauma
  • known brain tumors
  • pre-existing neurological disorders complicating assessment
  • neuroimaging at a hospital outside before transfer

and therefore may not apply to patients with these features.

TBI on CT was defined as any of:

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Article information

rID: 54351
Section: Approach
Synonyms or Alternate Spellings:
  • PECARN score
  • PECARN rule

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