title: Predictive value of initial computerized tomography scan, intracranial pressure, and state of autoregulation in patients with traumatic brain injury.
abstract: OBJECTIVE
  The authors explored the relationship between computerized tomography (CT) scan findings and intracranial pressure (ICP) measurements obtained in the first 24 hours of monitoring to identify parameters predicting outcome in patients with severe traumatic brain injury (TBI).
  
  
  METHODS
  Intracranial pressure, mean arterial blood pressure, cerebral perfusion pressure (CPP), and pressure reactivity index were measured continuously in 126 patients with severe TBI who were admitted to a neuroscience critical care unit. Mean values in the initial 24 hours of monitoring and in the total period of monitoring were compared with types of injury categorized on the basis of the initial CT scan according to the classification of Marshall, et al., and with Glasgow Outcome Scale scores. The initial CT scan classification correlated significantly but weakly with ICP measured during the first 24 hours of monitoring (p = 0.036) but not with mean ICP over the total time of intensive care. Both midline shift and the ratio of frontal horn diameter to internal diameter correlated with ICP in the first 24 hours (p < 0.007) and with ICP over the total monitoring period (p < 0.03). Outcome score correlated with initial CT scan findings (p = 0.018), ICP over the total monitoring period (p < 0.0023), pressure reactivity over the total monitoring period (p < 0.0002), and pressure reactivity in the first 24 hours (p < 0.0001) but not with ICP in the first 24 hours. Patients with disturbed pressure reactivity in the first 24 hours after injury had a significantly higher mortality rate than patients with intact pressure reactivity (28.6% compared with 9.5%; p < 0.001).
  
  
  CONCLUSIONS
  Patients with severe TBI who have early loss of autoregulation have a worse prognosis. Mean ICP values in patients with diffuse TBI cannot be predicted by using the Marshall CT scan classification.
authors.affiliation: Academic Neurosurgical Unit, Department of Clinical Neuroscience, University of Cambridge, Addenbrooke's NHS Trust, Cambridge, United Kingdom.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Hiler
authors.forename: Marek
authors.initials: M
authors.lastname: Czosnyka
authors.forename: Peter
authors.initials: P
authors.lastname: Hutchinson
authors.forename: Marcella
authors.initials: M
authors.lastname: Balestreri
authors.forename: Peter
authors.initials: P
authors.lastname: Smielewski
authors.forename: Basil
authors.initials: B
authors.lastname: Matta
authors.forename: John D
authors.initials: JD
authors.lastname: Pickard
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000502:physiology; D001921:Brain / Q000098:blood supply; D001930:Brain Injuries / Q000000981:diagnostic imaging* / Q000401:mortality / Q000503:physiopathology; D004739:England; D005260:Female; D023261:Glasgow Outcome Scale; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007362:Intensive Care Units; D007427:Intracranial Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D011379:Prognosis; D012189:Retrospective Studies; D013223:Statistics as Topic; D015996:Survival Rate; D014057:Tomography, X-Ray Computed