title: Are optimal cerebral perfusion pressure and cerebrovascular autoregulation related to long-term outcome in patients with aneurysmal subarachnoid hemorrhage?
abstract: OBJECTIVE
  Continuous assessment of the cerebrovascular autoregulation (CVA) through use of the pressure reactivity index (PRx), a moving linear correlation coefficient between mean arterial blood pressure and intracranial pressure, has been effective in optimizing cerebral perfusion pressure (CPPopt) in traumatic brain injured (TBI) patients. This study investigates the feasibility of measuring CPPopt in patients with aneurysmal subarachnoid hemorrhage (aSAH) by continuously assessing the CVA.
  
  
  METHODS
  Twenty-nine aSAH patients were enrolled, and data from CVA status, CPPopt, and periods when CPP was below, within, or above CPPopt were computed daily. Outcome was assessed at 6 months with the Glasgow Outcome Scale. Mann-Whitney U test was used to analyze differences in the duration of impaired CVA and duration of CPP below CPPopt in patients with good and poor outcomes. Multivariable logistic regression analysis was used to identify independent predictors of outcome.
  
  
  RESULTS
  CVA monitoring data were available for all 29 patients with a total monitoring time of 2757 h. The duration of impaired CVA was 36.5% (interquartile range: 24.6 to 49.8) of the total monitoring time in 15 patients with good outcome and 71.6% of the total monitoring time (51.2 to 80.0) in 14 patients with poor outcome (Mann-Whitney U test 3.295, P=0.0010). PRx-based CPPopt could be identified in 26 patients (89.6%) with a total monitoring time of 2691 h. The duration of CPP below the CPPopt range was 28.0% (interquartile range: 18.0 to 47.0) of the total monitoring time in patients with good outcome and 76.0% (48.5 to 82.5) in patients with poor outcome (Mann-Whitney U test 2.779, P=0.0054). Glasgow Coma Scale score and duration of impaired CVA were independently associated with 6-month outcome (Glasgow Coma Scale score odds ratio: 1.95, 95% confidence interval: 1.01-3.75; duration of impaired CVA odds ratio: 0.88, 95% confidence interval: 0.78-0.99).
  
  
  CONCLUSIONS
  The assessment of CVA and CPPopt is feasible in aSAH patients and may provide important information regarding long-term outcome. A PRx above the 0.2 threshold and a CPP below the CPPopt range are associated with worse outcome.
authors.affiliation: Department of Neuroanesthesia-Neurointensive Care, University of Brescia, Spedali Civili, Brescia, Italy. rasulo@med.unibs.it
authors.forename: Frank Anthony
authors.initials: FA
authors.lastname: Rasulo
authors.forename: Alan
authors.initials: A
authors.lastname: Girardini
authors.forename: Andrea
authors.initials: A
authors.lastname: Lavinio
authors.forename: Elena
authors.initials: E
authors.lastname: De Peri
authors.forename: Roberto
authors.initials: R
authors.lastname: Stefini
authors.forename: Marco
authors.initials: M
authors.lastname: Cenzato
authors.forename: Ilaria
authors.initials: I
authors.lastname: Nodari
authors.forename: Nicola
authors.initials: N
authors.lastname: Latronico
mesh_terms: D000328:Adult; D000368:Aged; D001794:Blood Pressure / Q000502:physiology*; D002545:Brain Ischemia / Q000209:etiology / Q000503:physiopathology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D003627:Data Interpretation, Statistical; D005240:Feasibility Studies; D005260:Female; D015600:Glasgow Coma Scale; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D007427:Intracranial Pressure / Q000502:physiology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D009422:Nervous System Diseases / Q000209:etiology; D019635:Neurosurgical Procedures; D010477:Perfusion; D011183:Postoperative Complications / Q000503:physiopathology; D013345:Subarachnoid Hemorrhage / Q000503:physiopathology* / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D020301:Vasospasm, Intracranial / Q000209:etiology / Q000503:physiopathology