Global cerebral blood flow and CPP after severe XXXX : a xenon-CT study.

@entity1 @entity26 @entity542 @entity880 @entity130
OBJECTIVE: To evaluate the association between global cerebral blood flow and different cerebral perfusion pressure ranges in severe @entity542 . DESIGN: A retrospective study SETTING: Neurosurgical and @entity130 @entity1 in an intensive care unit in a regional hospital. @entity1 AND @entity1 : Out of a series of 237 consecutive @entity1 with severe @entity542 (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 @entity1 nor any mistakenly diagnosed as severe on entry. INTERVENTIONS: None. MEASUREMENTS AND 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 @entity26 and @entity880 . CONCLUSIONS: There was little correlation between CPP values and global cerebral blood flow levels in our selected @entity1 , probably because pressure autoregulation was preserved. Global metabolism measurements were constant within the groups, suggesting that in @entity1 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.
