PECARN Calculator

Pediatric Emergency Care Applied Research Network head injury assessment

Patient Assessment

PECARN criteria apply to children under 18 years

High-Risk Criteria (<2 years)

Any of these criteria indicate high risk for clinically important TBI:

Intermediate-Risk Criteria (<2 years)

These criteria may warrant further evaluation:

PECARN Assessment Results

Very Low Risk

Very low risk for clinically important traumatic brain injury

TBI Risk: <0.05%
CT Not Routinely Needed

Primary Recommendation

CT scan not recommended

Clinical Recommendations

  • CT scan not routinely recommended
  • Provide caregiver with head injury instructions
  • Advise when to return for medical care
  • Consider other causes of symptoms if present

Example Cases

High Risk Case

Patient: 18-month-old with GCS 13 after fall from stairs
Assessment: High risk criteria present (GCS <15)
Recommendation: CT scan recommended

Intermediate Risk Case

Patient: 4-year-old with vomiting after bicycle accident
Assessment: Intermediate risk criteria present
Recommendation: Consider CT or observation period

Low Risk Case

Patient: 3-year-old with minor bump, no symptoms
Assessment: No high or intermediate risk criteria
Recommendation: CT scan not routinely needed

About PECARN

PECARN (Pediatric Emergency Care Applied Research Network) provides evidence-based decision rules for pediatric head injuries.

Reduces unnecessary CT radiation exposure
Identifies high-risk patients needing immediate imaging
Supports clinical decision-making

Risk Categories

High Risk

TBI risk: ~4.4%

CT scan recommended

Intermediate Risk

TBI risk: ~0.9%

Clinical judgment needed

Very Low Risk

TBI risk: <0.05%

CT not routinely needed

Key Definitions

Altered Mental State:

Agitation, somnolence, slow response, repetitive questioning

Severe Injury Mechanism:

MVC with ejection/rollover/death, significant fall, high-impact strike

Clinically Important TBI:

Brain injury requiring neurosurgical intervention or resulting in death

Red Flags

Immediate Attention:
  • Persistent vomiting
  • Seizures
  • Focal neurological deficits
  • Signs of increased ICP
Monitor Closely:
  • Worsening headache
  • Behavioral changes
  • Difficulty staying awake
  • Balance problems

Understanding PECARN Guidelines

Clinical Purpose

The PECARN decision rules help clinicians identify children at very low risk for clinically important traumatic brain injuries, reducing unnecessary CT exposure while ensuring appropriate imaging for high-risk patients.

Age-Based Approach

  • <2 years: Includes parental concern and scalp hematoma
  • ≥2 years: Includes vomiting and severe headache
  • Different LOC thresholds by age group
  • All groups: GCS, skull fracture, altered mental state

Clinical Implementation

PECARN rules should be integrated with clinical judgment, family preferences, and institutional protocols. They provide guidance but do not replace comprehensive clinical assessment.

Limitations

Important: PECARN rules apply only to children with head trauma presenting within 24 hours of injury and do not replace clinical judgment for patients with penetrating injuries or pre-existing neurological disorders.

Critical Medical Disclaimer

This calculator is for educational purposes only and should never replace professional medical evaluation. Pediatric head injuries require careful clinical assessment by qualified healthcare professionals. The PECARN rules are decision support tools that must be used in conjunction with clinical judgment, patient/family preferences, and institutional protocols. Always seek immediate medical attention for any child with a significant head injury. This tool should only be used by trained healthcare professionals familiar with pediatric emergency medicine.