Sorts children with minor head trauma (GCS 14 or 15) into high, intermediate or very low risk of a clinically important brain injury, to guide the decision on a head CT.
Result
Choose the age group and GCS, then mark the findings that are present.
Sources
3 studies
3
studies
1,667
citations
175
PubMed papers
Evidence
Known limitations
In 42,412 children with head trauma, the validated age-specific rules had negative predictive values of 100% under 2 years and 99.95% from 2 years, with sensitivities of 100% (25 of 25) and 96.8% (61 of 63), and missed no child who needed neurosurgery.
In 20,137 children in Australia and New Zealand, PECARN applied to about three quarters of them and was 100% sensitive under 2 years (38 of 38) and 99% from 2 years (97 of 98) for clinically important brain injury, the highest point sensitivities of the three rules; with a common outcome in 18,913 children with mild injuries, the sensitivities of the three rules were similar.
In a French multicenter prospective study of 1,499 children, PECARN identified all 9 children with a clinically important brain injury (sensitivity 100%, negative predictive value 100%), supporting its use outside North America.
Scand J Trauma Resusc Emerg Med: Journal Metrics Score 3.1, Q1 · cited 77 times
PubMed · Free full text · DOI
The original paper has been cited 1,667 times, and 175 PubMed articles mention the PECARN head injury rule in their title or abstract. Citation counts from OpenAlex and article counts from PubMed, retrieved November 12, 2026. Journal Metrics Scores and quartiles are from this site’s current release; follow the journal name for details.
After the result
High risk · Intermediate risk · Very low risk
CT recommended. Observation or CT. CT not recommended.
Next steps
Avoid common errors
4 common errors to avoid
and 2 more
When the rule does not fit
1Outside the derivation population
The rule was not built for children with a GCS of 13 or less, penetrating trauma, bleeding disorders, ventricular shunts, brain tumors or injuries more than 24 hours old.
2Non-accidental injury
An unclear or changing history, especially in infants, needs its own assessment; a very low PECARN risk does not rule out abuse.
3Age-specific items
A palpable skull fracture is a PECARN predictor only under 2 years, and vomiting and severe headache count only from 2 years; mixing the two lists misclassifies children. A palpable or depressed skull fracture is still a reason for CT at any age.
4Not a rule for other causes
PECARN estimates the risk of a traumatic brain injury. A headache or vomiting with another cause, such as a tumor, is outside what it can exclude.
Formula
Any high-risk predictor: CT recommended. Otherwise any intermediate predictor: observation or CT. Otherwise very low risk: CT not recommended.
High → intermediate → very low
Any high-risk predictor: CT recommended. Otherwise any intermediate predictor: observation or CT. Otherwise very low risk: CT not recommended.
Rule and risk groups
| Step | Under 2 years | 2 years and older |
|---|---|---|
| High risk: any of | GCS 14; Other signs of altered mental status; Palpable skull fracture | GCS 14; Other signs of altered mental status; Signs of basilar skull fracture |
| Otherwise intermediate: any of | Occipital, parietal or temporal scalp hematoma; Loss of consciousness for 5 seconds or more; Severe mechanism of injury; Not acting normally per parent | Any loss of consciousness; Severe mechanism of injury; Vomiting; Severe headache |
| Severe mechanism | Fall of more than 3 feet (0.9 m); ejection, rollover or death of a passenger in a vehicle crash; unhelmeted pedestrian or bicyclist struck by a vehicle; head struck by a high-impact object | The same, with a fall of more than 5 feet (1.5 m) |
| Group | Under 2 | 2 and older | Recommendation |
|---|---|---|---|
| Very low risk | under 0.02% | under 0.05% | CT not recommended |
| Intermediate risk | 0.9% | 0.9% | Observation or CT |
| High risk | 4.4% | 4.3% | CT recommended |
Kuppermann 2009
Clinically important brain injury
Other rules
Test cases
3 published cases, each also a test case
3 published cases; the calculator reproduces every result.
Worked examples
A 7-year-old boy came to the emergency department after a ground-level fall at school with no loss of consciousness, no nausea or vomiting and no change in alertness. He was awake and alert with a GCS of 15 and a normal neurological examination. The clinician applied PECARN and placed him in the lowest risk group, so CT was not indicated for head injury. On reassessment his mother reported about 4 months of headaches and dizziness before the fall; a head CT then showed a right cerebellar mass, confirmed on MRI and resected as an atypical teratoid rhabdoid tumor.
“was in the lowest risk group for clinically important traumatic brain injury by the PECARN criteria”
He had mild intermittent headaches for months before the fall, not a severe headache, so no predictor was present. The authors’ point is that PECARN rules out traumatic brain injury, not every cause of headache. Dizziness after the fall is not a PECARN predictor, and it also means the fall was not a ‘trivial’ ground-level injury excluded from the study.
Entered as: Age: 2 years and older; Glasgow Coma Scale: 15; Other signs of altered mental status: no; Palpable skull fracture (under 2 years): no; Signs of basilar skull fracture (2 years and older): no; Occipital, parietal or temporal scalp hematoma (under 2 years): no; Loss of consciousness: no; Severe mechanism of injury: no; Not acting normally per parent (under 2 years): no; Vomiting (2 years and older): no; Severe headache (2 years and older): no.
Source: Iqbal L et al., J Am Coll Emerg Physicians Open 2021 (PubMed · Free full text · DOI)
A 4-year-old boy without a helmet, sitting on his father’s lap on a motorcycle, was thrown forward in a collision and struck his face on the asphalt. His father reported loss of consciousness for less than 5 minutes; he had no vomiting, a GCS of 15 and no focal deficit. CT showed a retroclival epidural hematoma, managed without surgery, and mandibular fractures, which were fixed surgically.
“there was a loss of consciousness for less than 5 minutes”
PECARN’s severe-mechanism list does not name motorcycle crashes; we counted an unhelmeted child thrown from a motorcycle in a collision as the equivalent of ejection from a vehicle. The loss of consciousness alone places him in the intermediate group either way. The case shows why several findings, rather than one, push towards CT.
Entered as: Age: 2 years and older; Glasgow Coma Scale: 15; Other signs of altered mental status: no; Palpable skull fracture (under 2 years): no; Signs of basilar skull fracture (2 years and older): no; Occipital, parietal or temporal scalp hematoma (under 2 years): no; Loss of consciousness: yes; Severe mechanism of injury: yes; Not acting normally per parent (under 2 years): no; Vomiting (2 years and older): no; Severe headache (2 years and older): no.
Source: Lauren C et al., J Cent Nerv Syst Dis 2025 (PubMed · Free full text · DOI)
A 14-year-old boy fell from a moving vehicle, lost consciousness briefly and reported a headache. His GCS was 14 because of mild confusion, and he had a boggy scalp with a palpable skull fracture near the midline. CT showed a diastatic, depressed left parietal fracture over the superior sagittal sinus with a large subgaleal hematoma; CT venography showed thrombosis and MRI injury of the sinus.
“Glasgow Coma Scale score was 14 because of mild confusion”
A GCS of 14 alone places a child in the high-risk group. A palpable skull fracture is a PECARN predictor only under 2 years, so the rule does not count it at 14 years, but a palpable, depressed fracture is a reason for CT at any age. As in the motorcycle case, we counted the fall from a moving vehicle as equivalent to ejection; the headache was not described as severe. Neither changes the group.
Entered as: Age: 2 years and older; Glasgow Coma Scale: 14; Other signs of altered mental status: no; Palpable skull fracture (under 2 years): yes; Signs of basilar skull fracture (2 years and older): no; Occipital, parietal or temporal scalp hematoma (under 2 years): no; Loss of consciousness: yes; Severe mechanism of injury: yes; Not acting normally per parent (under 2 years): no; Vomiting (2 years and older): no; Severe headache (2 years and older): no.
Source: Zoerner DM et al., J Neurosurg Case Lessons 2022 (PubMed · Free full text · DOI)
FAQ
7 questions and answers
and 5 more answers
Questions
It is a clinical decision rule from the Pediatric Emergency Care Applied Research Network (Kuppermann 2009) that identifies children with minor head trauma who are at very low risk of a clinically important traumatic brain injury and do not need a CT scan. It has separate versions for children under 2 years and from 2 years.
High risk: GCS 14, other signs of altered mental status, or signs of basilar skull fracture; CT is recommended. Intermediate risk: any loss of consciousness, vomiting, a severe mechanism of injury or a severe headache; observation or CT. With none of these, the child is at very low risk and CT is not recommended.
High risk: GCS 14, other signs of altered mental status, or a palpable skull fracture. Intermediate risk: an occipital, parietal or temporal scalp hematoma, loss of consciousness for 5 seconds or more, a severe mechanism of injury, or not acting normally according to the parent. With none of these, CT is not recommended.
A motor vehicle crash with ejection, death of another passenger or rollover; a pedestrian or bicyclist without a helmet struck by a motor vehicle; a fall of more than 3 feet (under 2 years) or more than 5 feet (2 years and older); or the head struck by a high-impact object.
In the validation cohorts of the original study, the rule for children under 2 found all 25 children with a clinically important brain injury (sensitivity 100%) and the rule from 2 years found 61 of 63 (96.8%); neither missed a child who needed neurosurgery. In 20,137 children in Australia and New Zealand, PECARN was 100% sensitive under 2 years and 99% from 2 years in the children it applied to (38 of 38 and 97 of 98), the highest point sensitivities of the three rules tested; CATCH and CHALICE were each assessed against their own outcome (Babl 2017).
It means CT is not recommended on the basis of the head injury findings. Worsening symptoms, concern about abuse, a bleeding disorder, a ventricular shunt or other reasons for concern still call for clinical judgment, and the rule does not apply to a GCS of 13 or less.
Children seen more than 24 hours after the injury, those with a GCS of 13 or less, penetrating trauma, known brain tumors, pre-existing neurological disorders that complicate assessment, ventricular shunts or bleeding disorders, and those already imaged elsewhere were excluded from the study or from the analysis that built the rule.
Further reading
6 references with PubMed and DOI links
6
references
4
free full text
From Kuppermann N et al., Lancet 2009 to the newest case reports.
References
Contributed by Dr. Meng Zhao (MD · Former Neurosurgeon · Medical AI Researcher), from the original publications listed here. Last updated November 12, 2026. LinkedIn
The calculator code is tested against every worked example on this page before each release.
This calculator supports, and does not replace, clinical judgment. It is meant for healthcare professionals and is not medical advice for patients. Report an error through the contact page.
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