Objective To determine the prevalence of clinically important traumatic brain injuries (TBIs) with severe injury mechanisms in children with minor blunt head trauma but with no other risk factors from the Pediatric Emergency Care Applied Research Network (PECARN) TBI prediction rules (defined as isolated severe injury mechanisms).
Design Secondary analysis of a large prospective observational cohort study.
Setting Twenty-five emergency departments participating in the PECARN.
Patients Children with minor blunt head trauma and Glasgow Coma Scale scores of at least 14.
Intervention Treating clinicians completed a structured data form that included injury mechanism (severity categories defined a priori).
Main Outcome Measures Clinically important TBIs were defined as intracranial injuries resulting in death, neurosurgical intervention, intubation for more than 24 hours, or hospital admission for at least 2 nights. We investigated the rate of clinically important TBIs in children with either severe injury mechanisms or isolated severe injury mechanisms.
Results Of the 42 412 patients enrolled in the overall study, 42 099 (99%) had injury mechanisms recorded, and their data were included for analysis. Of all study patients, 5869 (14%) had severe injury mechanisms, and 3302 (8%) had isolated severe injury mechanisms. Overall, 367 children had clinically important TBIs (0.9%; 95% CI, 0.8%-1.0%). Of the 1327 children younger than 2 years with isolated severe injury mechanisms, 4 (0.3%; 95% CI, 0.1%-0.8%) had clinically important TBIs, as did 12 of the 1975 children 2 years or older (0.6%; 95% CI, 0.3%-1.1%).
Conclusion Children with isolated severe injury mechanisms are at low risk of clinically important TBI, and many do not require emergent neuroimaging.