Evaluation of the PECARN rule for traumatic brain injury applied to infants younger than 3 months and creation of a modified, age-specific rule

Infants < 3 months with minor head trauma (MHT) are a particularly vulnerable group, though few studies have focused specifically on these patients. We aimed to evaluate the application of the PECARN prediction rule, designed for clinically important traumatic brain injury (ciTBI) in children < 2 years in infants < 3 months, and create a specific prediction rule for this population. We conducted a prospective multicenter observational study in 13 pediatric emergency departments (PEDs) in Spain. The PECARN rule was applied to all patients. A new specific prediction rule for infants < 3 months of age was created. The main outcome measures were (1) ciTBI, (2) TBI evidenced on computed tomography (CT) scan, and (3) isolated skull fracture (ISF). Telephone follow-up was conducted for all patients over the 4 weeks after the initial PED visit. Of 21,981 children with MHT, 366 (1.7%) were < 3 months old and 195 (53.3%) underwent neuroimaging, including 37 (10.1%) with CT scan. The sensitivity and negative predictive value (NPV) of the PECARN prediction rule for ciTBI were 100% (95% CI, 20.7–100) and 99.7% (95% CI, 98.4–100%), respectively. Of the 230 infants (62.8%) who met the PECARN low-risk criteria, none had ciTBI, 1 (0.4% overall, 95% CI, 0–2.4) had TBI on CT, and 2 (0.9% overall; 95% CI, 0.1–3.1) had an ISF. Among the 136 infants (37.2%) who did not meet the PECARN low-risk criteria, 1 (0.3% overall; 95% CI, 0–1.5) had ciTBI, 11 (8.1% overall; 95% CI, 4.1–14.0) had TBI on CT, and 18 (13.2% overall; 95% CI, 8–20.1) had an ISF. The sensitivity and NPV of the Spanish prediction rule for ciTBI were 100% (95% CI, 20.7–100) and 100% (95% CI, 98.4–100%), respectively. No infants in the registry developed complications during follow-up. Conclusion: The PECARN rule for infants < 2 years old accurately identified infants < 3 months old at low risk for ciTBI in our population, although the adapted Spanish rule presented here could be even more accurate.What is Known:• Infants younger than 3 months are vulnerable to minor blunt head trauma due to their age and to difficulties in assessing the subtle symptoms and minimal physical findings detected on examination.• A low threshold for CT scan is recommended in this population.What is New:• PECARN rule for infants < 2 years old is an adequate tool with which to identify infants < 3 months old at low risk for clinically important traumatic brain injury.• Spanish rule could identify even more low-risk infants without overlooking important outcomes but it should be validated to confirm its predictive capacity. © 2022, The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.