title: Should the neurointensive care management of traumatic brain injury patients be individualized according to autoregulation status and injury subtype?
abstract: BACKGROUND
  The status of autoregulation is an important prognostic factor in traumatic brain injury (TBI), and is important to consider in the management of TBI patients. Pressure reactivity index (PRx) is a measure of autoregulation that has been thoroughly studied, but little is known about its variation in different subtypes of TBI. In this study, we examined the impact of PRx and cerebral perfusion pressure (CPP) on outcome in different TBI subtypes.
  
  
  METHODS
  107 patients were retrospectively studied. Data on PRx, CPP, and outcome were collected from our database. The first CT scan was classified according to the Marshall classification system. Patients were assigned to "diffuse" (Marshall class: diffuse-1, diffuse-2, and diffuse-3) or "focal" (Marshall class: diffuse-4, evacuated mass lesion, and non-evacuated mass lesion) groups. 2 × 2 tables were constructed calculating the proportions of favorable/unfavorable outcome at different combinations of PRx and CPP.
  
  
  RESULTS
  Low PRx was significantly associated with favorable outcome in the combined group (p = 0.002) and the diffuse group (p = 0.04), but not in the focal group (p = 0.06). In the focal group higher CPP values were associated with worse outcome (p = 0.02). In diffuse injury patients with disturbed autoregulation (PRx >0.1), CPP >70 mmHg was associated with better outcome (p = 0.03).
  
  
  CONCLUSIONS
  TBI patients with diffuse injury may differ from those with mass lesions. In the latter higher levels of CPP may be harmful, possibly due to BBB disruption. In TBI patients with diffuse injury and disturbed autoregulation higher levels of CPP may be beneficial.
authors: Department of neuroscience, section of neurosurgery, Uppsala University Hospital, 75185, Uppsala, Sweden, ulf.johnson@neuro.uu.se.
authors: Ulf
authors: U
authors: Johnson
authors: Anders
authors: A
authors: Lewén
authors: Elisabeth
authors: E
authors: Ronne-Engström
authors: Tim
authors: T
authors: Howells
authors: Per
authors: P
authors: Enblad
mesh_terms: D000328:Adult; D001794:Blood Pressure / Q000502:physiology*; D001930:Brain Injuries / Q000145:classification* / Q000628:therapy*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D003422:Critical Care / Q000379:methods*; D005260:Female; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D016896:Treatment Outcome