Young age as a risk factor for impaired cerebral autoregulation after moderate to severe pediatric traumatic brain injury

Background: Little is known about age and cerebral autoregulation in children with traumatic brain injury (TBI). The authors compared cerebral autoregulation between young (aged <4 yr) and older (aged >= 4 yr) children with TBI. Methods. After University of Washington's institutional review board approval, a retrospective analysis of prospectively collected data (May 2002 and June 2007) was performed. Eligibility criteria included age 16 yr or younger, moderate to severe (admission Glasgow Coma Scale score <13) TBI, TBI on computed tomography scan, and tracheal intubation. Cerebral antoregulation testing was performed within 72 h after TBI, and antoregulation was quantified using the autoregulatory index. An antoregulatory index less than 0.4 represents impaired cerebral autoregulation. The 12-month Glasgow outcome score was measured. Data arc presented as mean +/- SD or range. Results: Thirty-seven children (8.9 +/- 5.1 yr; 0.8-16 yr) were enrolled. Children younger than 4 yr had a higher incidence of impaired cerebral autoregulation (8 of 10 vs. 7 of 27; P = 0.006) and worse 12-month outcome (Glasgow outcome score 3.0 +/- 1.0 vs. 4.0 +/- 1.0; P = 0.02) than older children. Age less than 4 yr (adjusted odds ratio, 12.2; 95% confidence interval, 1.5-98-5) and low Glasgow Coma Scale score (adjusted odds ratio for higher Glasgow Coma Scale, 0.53; 95% confidence interval, 0.30-0.96) were independently associated with impaired cerebral autoregulation. Conclusions: Age less than 4 yr was a risk factor for impaired cerebral autoregulation, independent of TBI severity. Age-related factors may play a role in the mechanisms maintaining or worsening cerebral autoregulation in children after TBI.