Risk of Traumatic Brain Injuries in Infants Younger than 3 Months With Minor Blunt Head Trauma

Study objective: Infants with head trauma often have subtle findings suggestive of traumatic brain injury. Prediction rules for traumatic brain injury among children with minor head trauma have not been specifically evaluated in infants younger than 3 months old. We aimed to determine the risk of clinically important traumatic brain injuries, traumatic brain injuries on computed tomography (CT) images, and skull fractures in infants younger than 3 months of age who did and did not meet the age-specific Pediatric Emergency Care Applied Research Network (PECARN) low-risk criteria for children with minor blunt head trauma. Methods: We conducted a secondary analysis of infants <3 months old in the public use data set from PECARN's prospective observational study of children with minor blunt head trauma. Main outcomes included (1) clinically important traumatic brain injury, (2) traumatic brain injury on CT, and (3) skull fracture on CT. Results: Of 10,904 patients <2 years old, 1,081 (9.9%) with complete data were <3 months old; most (750/1081, 69.6%) sustained falls, and 633/1081 (58.6%) underwent CT scans. Of the 514/1081 (47.5%) infants who met the PECARN low-risk criteria, 1/514 (0.2%, 95% confidence interval [CI] 0.005% to 1.1%), 10/197 (5.1%, 2.5% to 9.1%), and 9/197 (4.6%, 2.1% to 8.5%) had clinically important traumatic brain injuries, traumatic brain injuries on CT, and skull fractures, respectively. Of 567 infants who did not meet the low-risk PECARN criteria, 24/567 (4.2%, 95% CI 2.7% to 6.2%), 94/436 (21.3%, 95% CI 17.6% to 25.5%), and 122/436 (28.0%, 95% CI 23.8% to 32.5%) had clinically important traumatic brain injuries, traumatic brain injuries, and skull fractures, respectively. Conclusion: The PECARN traumatic brain injury low-risk criteria accurately identified infants <3 months old at low risk of clinically important traumatic brain injuries. However, infants at low risk for clinically important traumatic brain injuries remained at risk for traumatic brain injuries on CT, suggesting the need for a cautious approach in these infants.