title: Cerebrovascular response in children following severe traumatic brain injury.
abstract: OBJECTIVE
  To describe the pathophysiologic response in cerebral blood flow (CBF) and autoregulation after severe traumatic brain injury (TBI), Glasgow Coma Score (GCS) ≤8 on admission, in children, defining a baseline for future studies.
  
  
  METHODS
  Retrospective chart review of 95 patients following TBI, ages 0.1-18.4 years (<5 years (n = 44), <2 years (n = 17)) for CBF using Xenon Computerized Tomography (XeCT) over a 10-year period and 6-month Glasgow Outcome Scores (GOS). A total of 140 CBF studies were performed variably from admission up to post injury day (PID) 9; 27 patients underwent repeat CBF study after PaCO(2) was manipulated to determine CO(2) vasoreactivity (CO(2)VR).
  
  
  RESULTS
  Mean CBF on admission (PID 0, n = 26) was 32.05 ± 21.45 ml/100 g/min (mean ± SEM) and was ≤20 ml/100 g/min in eight patients. At PID 1-2, mean CBF increased to 55.36 ± 23.11 ml/100 g/min. There was significant differences in mean CBF of "favorable" outcomes (GOS ≥ 4) versus "unfavorable" outcome (GOS ≤ 3) (61.74 ± 18.27 vs. 46.54 ± 26.26, respectively (P = 0.01)). "Unfavorable" outcomes were seen in all patients with CBF ≤20 ml/100 mg/min during PID 0-2 and in 76.5% of children <2 years. CO(2)VR <2%/Torr PaCO(2) within PID 0-2 was significantly associated with "unfavorable" outcome (P = 0.029).
  
  
  CONCLUSIONS
  Younger age, early or later low CBF, and CO(2)VR <2%/Torr PaCO(2) were correlated with poorer outcomes in children. This represents the largest experience with XeCT CBF in children and confirms our preliminary report of low early CBF after TBI in children, disturbed CO(2)VR, and relationship of low CBF and unfavorable outcome.
authors.affiliation: Phoenix Children's Neuroscience Institute and Pediatric Neurosurgery, AZ 85016, USA. dadelson@phoenixchildrens.com
authors.forename: P David
authors.initials: PD
authors.lastname: Adelson
authors.forename: Ravi
authors.initials: R
authors.lastname: Srinivas
authors.forename: Yuefang
authors.initials: Y
authors.lastname: Chang
authors.forename: Michael
authors.initials: M
authors.lastname: Bell
authors.forename: Patrick M
authors.initials: PM
authors.lastname: Kochanek
mesh_terms: D000293:Adolescent; D000367:Age Factors; D001930:Brain Injuries / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D023261:Glasgow Outcome Scale; D006706:Homeostasis / Q000502:physiology; D006801:Humans; D007223:Infant; D008297:Male; D020127:Recovery of Function / Q000502:physiology*; D012189:Retrospective Studies