title: Global cerebral blood flow and CPP after severe head injury: a xenon-CT study.
abstract: OBJECTIVE
  To evaluate the association between global cerebral blood flow and different cerebral perfusion pressure ranges in severe head injury.
  
  
  METHODS
  A retrospective study
  
  
  METHODS
  Neurosurgical and trauma patients in an intensive care unit in a regional hospital.
  
  
  METHODS
  Out of a series of 237 consecutive patients with severe head injuries (GCS<or=8), 162 were submitted to ICP monitoring and 89 of them underwent 180 xenon-CT studies and cerebral perfusion pressure (CPP) measurement. The xenon-CT studies did not include any unsalvageable patients nor any mistakenly diagnosed as severe on entry.
  
  
  METHODS
  None.
  
  
  RESULTS
  Most (95.6%) of xenon-CT studies were obtained with CPP values within the 50-90 mmHg range. Perfusion data were grouped according to CPP values: (1) below 50 mmHg, (2) 50-60 mmHg, (3) 60-70 mmHg, (4) above 70 mmHg. Global cerebral blood flow did not differ among the groups (p=0.49). No differences in physiological variables were found among the CPP groups, except for intracranial pressure, higher in the group with CPP below 50 mmHg, and mean arterial pressure, higher in the CPP above 70 mmHg group (p<0.0001). No differences were found for cerebral metabolic rate of oxygen and lactate.
  
  
  CONCLUSIONS
  There was little correlation between CPP values and global cerebral blood flow levels in our selected patients, probably because pressure autoregulation was preserved. Global metabolism measurements were constant within the groups, suggesting that in patients with controlled physiological variables an interplay between cerebral blood flow and metabolism might be more relevant than the relationship between CPP and cerebral blood flow.
authors: U. O. Anestesia e Rianimazione, Ospedale M. Bufalini, viale Ghirotti 286, 47023, Cesena, Italy. achiere@ausl-cesena.emr.it.
authors: Arturo
authors: A
authors: Chieregato
authors: U. O. Anestesia e Rianimazione, Ospedale M. Bufalini, viale Ghirotti 286, 47023, Cesena, Italy.
authors: Alessandra
authors: A
authors: Tanfani
authors: U. O. Anestesia e Rianimazione, Ospedale M. Bufalini, viale Ghirotti 286, 47023, Cesena, Italy.
authors: Christian
authors: C
authors: Compagnone
authors: U. O. Anestesia e Rianimazione, Ospedale M. Bufalini, viale Ghirotti 286, 47023, Cesena, Italy.
authors: Claudia
authors: C
authors: Turrini
authors: U. O. Anestesia e Rianimazione, Ospedale M. Bufalini, viale Ghirotti 286, 47023, Cesena, Italy.
authors: Federica
authors: F
authors: Sarpieri
authors: U. O. Anestesia e Rianimazione, Ospedale M. Bufalini, viale Ghirotti 286, 47023, Cesena, Italy.
authors: Maurizio
authors: M
authors: Ravaldini
authors: U. O. Anestesia e Rianimazione, Ospedale M. Bufalini, viale Ghirotti 286, 47023, Cesena, Italy.
authors: Luigi
authors: L
authors: Targa
authors: U. O. Neuroradiologia, Ospedale S. Anna, Ferrara, Italy.
authors: Enrico
authors: E
authors: Fainardi
mesh_terms: D000328:Adult; D001921:Brain / Q000098:blood supply*; D006259:Craniocerebral Trauma / Q000145:classification* / Q000503:physiopathology / Q000628:therapy; D005260:Female; D023261:Glasgow Outcome Scale / Q000706:statistics & numerical data*; D006801:Humans; D015601:Injury Severity Score; D007427:Intracranial Pressure; D008297:Male; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D014978:Xenon
chemical_list: D014978:Xenon