Isolated loss of consciousness in children with minor blunt head trauma.

IMPORTANCE: A history of loss of consciousness (LOC) is frequently a driving factor for computed tomography use in the emergency department evaluation of children with blunt head trauma. Computed tomography carries a nonnegligible risk for lethal radiation-induced malignancy. The Pediatric Emergency Care Applied Research Network (PECARN) derived 2 age-specific prediction rules with 6 variables for clinically important traumatic brain injury (ciTBI), which included LOC as one of the risk factors.

OBJECTIVE: To determine the risk for ciTBIs in children with isolated LOC.

DESIGN, SETTING, AND PARTICIPANTS: This was a planned secondary analysis of a large prospective multicenter cohort study. The study included 42 ,412 children aged 0 to 18 years with blunt head trauma and Glasgow Coma Scale scores of 14 and 15 evaluated in 25 emergency departments from 2004-2006.

EXPOSURE: A history of LOC after minor blunt head trauma.

MAIN OUTCOMES AND MEASURES: The main outcome measures were ciTBIs (resulting in death, neurosurgery, intubation for >24 hours, or hospitalization for ≥2 nights) and a comparison of the rates of ciTBIs in children with no LOC, any LOC, and isolated LOC (ie, with no other PECARN ciTBI predictors).

RESULTS: A total of 42 412 children were enrolled in the parent study, with 40 693 remaining in the current analysis after exclusions. Of these, LOC occurred in 15.4% (6286 children). The prevalence of ciTBI with any history of LOC was 2.5% and for no history of LOC was 0.5% (difference, 2.0%; 95% CI, 1.7-2.5). The ciTBI rate in children with isolated LOC, with no other PECARN predictors, was 0.5% (95% CI, 0.2-0.8; 13 of 2780). When comparing children who have isolated LOC with those who have LOC and other PECARN predictors, the risk ratio for ciTBI in children younger than 2 years was 0.13 (95% CI, 0.005-0.72) and for children 2 years or older was 0.10 (95% CI, 0.06-0.19).

CONCLUSIONS AND RELEVANCE: Children with minor blunt head trauma presenting to the emergency department with isolated LOC are at very low risk for ciTBI and do not routinely require computed tomographic evaluation.