A decision rule for identifying children at low risk for brain injuries after blunt head trauma.

STUDY OBJECTIVE Computed tomography (CT) is frequently used in evaluating children with blunt head trauma. Routine use of CT, however, has disadvantages. Therefore, we sought to derive a decision rule for identifying children at low risk for traumatic brain injuries. METHODS We enrolled children with blunt head trauma at a pediatric trauma center in an observational cohort study between July 1998 and September 2001. We evaluated clinical predictors of traumatic brain injury on CT scan and traumatic brain injury requiring acute intervention, defined by a neurosurgical procedure, antiepileptic medications for more than 1 week, persistent neurologic deficits, or hospitalization for at least 2 nights. We performed recursive partitioning to create clinical decision rules. RESULTS Two thousand forty-three children were enrolled, 1,271 (62%) underwent CT, 98 (7.7%; 95% confidence interval [CI] 6.3% to 9.3%) had traumatic brain injuries on CT scan, and 105 (5.1%; 95% CI 4.2% to 6.2%) had traumatic brain injuries requiring acute intervention. Abnormal mental status, clinical signs of skull fracture, history of vomiting, scalp hematoma (in children < or =2 years of age), or headache identified 97/98 (99%; 95% CI 94% to 100%) of those with traumatic brain injuries on CT scan and 105/105 (100%; 95% CI 97% to 100%) of those with traumatic brain injuries requiring acute intervention. Of the 304 (24%) children undergoing CT who had none of these predictors, only 1 (0.3%; 95% CI 0% to 1.8%) had traumatic brain injury on CT, and that patient was discharged from the ED without complications. CONCLUSION Important factors for identifying children at low risk for traumatic brain injuries after blunt head trauma included the absence of: abnormal mental status, clinical signs of skull fracture, a history of vomiting, scalp hematoma (in children < or =2 years of age), and headache.