title: Temporal Profiles of Cerebral Perfusion Pressure After Subarachnoid Hemorrhage.
abstract: BACKGROUND
  Insufficient cerebral perfusion pressure (CPP) after aneurysmal subarachnoid hemorrhage can impair cerebral blood flow. We examined the temporal profiles of CPP change and tested whether these profiles were associated with delayed cerebral ischemia (DCI).
  
  
  METHODS
  CPP values were retrospectively reviewed for 238 subjects. Intracranial pressure and mean arterial pressure values were obtained every 2 hours for 14 days. Induced hypertension was utilized to prevent vasospasm. The linear and quadratic CPP changes over time were tested using growth curve analysis. Multivariable logistic regression was utilized to examine the association between DCI and percentages of CPP values of >110, >100, <70, and <60 mm Hg. DCI was defined as neurological deterioration because of impaired cerebral blood flow.
  
  
  RESULTS
  Between-subject differences accounted for 39% of variation in CPP values. There was a significant linear increase in CPP values over time (β = 0.06, SE = 0.006, p < .001). The covariance (-0.52, SE = 0.09, p < .001) between initial CPP and linear parameter was negative, indicating that subjects with high CPP on admission had a slower rate of increase whereas those with low CPP had a faster rate of increase. For every 10% increase in the proportion of CPP of >100 or >110 mm Hg, the odds of DCI increased by 1.21 and 1.43, respectively (p < .05).
  
  
  CONCLUSIONS
  The longer the time patients spent with high CPP, the greater the odds for DCI. When used prophylactically, induced hypertension contributes to higher CPP values. On the basis of the CPP trends and correlations observed, induced hypertension may not confer expected benefits in patients with aneurysmal subarachnoid hemorrhage.
authors.affiliation: Questions or comments about this article may be directed to Khalil M. Yousef, PhD RN, at K.yousef@ju.edu.jo. He is an Assistant Professor, Department of Clinical Nursing, School of Nursing, University of Jordan, Amman, Jordan. Jeffrey R. Balzer, PhD FASNM DABNM, is an Associate Professor of Neurological Surgery, School of Nursing, University of Pittsburgh, and Department of Neurosurgery and Neuroscience, University of Pittsburgh Medical Center, Pittsburgh, PA. Catherine M. Bender, PhD RN FAAN, is a Professor, School of Nursing, University of Pittsburgh, Pittsburgh, PA. Leslie A. Hoffman, PhD RN, is a Professor Emeritus, School of Nursing, University of Pittsburgh, Pittsburgh, PA. Samuel M. Poloyac, PhD PharmD, is a Professor, School of Pharmacy, University of Pittsburgh, Pittsburgh, PA. Feifei Ye, PhD, is an Assistant Professor, School of Education, University of Pittsburgh, Pittsburgh, PA. Paula R. Sherwood, PhD RN CNRN FAAN, is a Professor, Schools of Nursing and Medicine, University of Pittsburgh, Pittsburgh, PA.
authors.forename: Khalil M
authors.initials: KM
authors.lastname: Yousef
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Balzer
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Bender
authors.forename: Leslie A
authors.initials: LA
authors.lastname: Hoffman
authors.forename: Samuel M
authors.initials: SM
authors.lastname: Poloyac
authors.forename: Feifei
authors.initials: F
authors.lastname: Ye
authors.forename: Paula R
authors.initials: PR
authors.lastname: Sherwood
mesh_terms: D000328:Adult; D000368:Aged; D002545:Brain Ischemia / Q000451:nursing* / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D013345:Subarachnoid Hemorrhage / Q000451:nursing* / Q000503:physiopathology*; D055815:Young Adult