PECARN Criteria: A Validated Clinical Decision Rule for Pediatric Head Trauma
The PECARN (Pediatric Emergency Care Applied Research Network) criteria is a highly validated clinical decision rule that stratifies children with minor blunt head trauma into risk categories to identify those at very low risk for clinically important traumatic brain injury (ciTBI), with 99.9% negative predictive value and near 100% sensitivity, allowing safe avoidance of unnecessary CT scans. 1
Age-Specific Risk Stratification
PECARN provides separate criteria for two age groups:
Children < 2 years old:
- Very Low Risk (all criteria must be present):
- Normal mental status
- No scalp hematoma (except frontal)
- No loss of consciousness
- Non-severe injury mechanism
- Acting normally per parent
- No palpable skull fracture
Children ≥ 2 years old:
- Very Low Risk (all criteria must be present):
- Normal mental status
- No loss of consciousness
- No vomiting
- Non-severe injury mechanism
- No signs of basilar skull fracture
- No severe headache
Clinical Performance
The PECARN criteria demonstrate exceptional performance:
- For children ≥2 years: 96.8% sensitivity and 99.9% negative predictive value (NPV) for ciTBI 2
- For children <2 years: 100% sensitivity and 100% NPV for ciTBI 2
- Multiple validation studies have confirmed these high sensitivity rates 2, 1
Clinical Application Algorithm
- Assess age group (< 2 years or ≥ 2 years)
- Apply appropriate PECARN criteria based on age
- Determine risk category:
- Very low risk: Observation recommended, CT generally not needed
- Intermediate risk: Consider observation vs. CT based on other factors (physician experience, multiple vs. isolated findings, worsening symptoms, parental preference)
- High risk: CT scan recommended
Special Considerations
Infants <3 months: Represent a particularly vulnerable population with small but significant risk (0.4%) of traumatic brain injury on CT and isolated skull fractures (0.9%) 3. The PECARN rule still performs well in this age group but a more cautious approach is warranted 3, 4.
Observation period: Each additional hour of observation is associated with decreased CT utilization without missing significant injuries 1. Planned observation reduces CT use by 3.9% with no increase in missed injuries.
Non-accidental trauma: PECARN criteria are not designed for suspected abuse cases, which require a different evaluation approach 2.
Implementation Benefits
- Multiple studies have shown successful implementation of PECARN with high adherence rates (93.5%) and provider satisfaction (96%) 5
- Maintains safety while reducing unnecessary CT scans 6, 7
- Multicenter validation studies across different countries have confirmed its reliability 7
Common Pitfalls to Avoid
- Applying to inappropriate populations: PECARN is designed for minor blunt head trauma only, not penetrating injuries or suspected abuse
- Relying solely on skull radiographs: Up to 50% of intracranial injuries occur without skull fracture 1
- Incomplete assessment: All criteria must be met to classify a patient as very low risk
- Ignoring parental concerns: Children not acting normally per parents is an important criterion that should not be overlooked
The PECARN criteria represent the most widely validated clinical decision rule for pediatric head trauma and should be used to guide imaging decisions while reducing unnecessary radiation exposure.