title: Cerebrovascular dynamics with head-of-bed elevation in patients with mild or moderate vasospasm after aneurysmal subarachnoid hemorrhage.
abstract: BACKGROUND
  In patients with aneurysmal subarachnoid hemorrhage, elevation of the head of the bed during vasospasm has been limited in an attempt to minimize vasospasm or its sequelae or both. Consequently, some patients have remained on bed rest for weeks.
  
  
  OBJECTIVE
  To determine how elevations of the head of the bed of 20 degrees and 45 degrees affect cerebrovascular dynamics in adult patients with mild or moderate vasospasm after aneurysmal subarachnoid hemorrhage and to describe the response of mild or moderate vasospasm to head-of-bed elevations of 20 degrees and 45 degrees with respect to variables such as grade of subarachnoid hemorrhage and degree of vasospasm.
  
  
  METHODS
  A within-patient repeated-measures design was used. The head of the bed was positioned in the sequence of 0 degrees -20 degrees -45 degrees -0 degrees in 20 patients with mild or moderate vasospasm between days 3 and 14 after aneurysmal subarachnoid hemorrhage. Continuous transcranial Doppler recordings were obtained for 2 to 5 minutes after allowing approximately 2 minutes for stabilization in each position.
  
  
  RESULTS
  No patterns or trends indicated that having the head of the bed elevated increases vasospasm. As a group, there were no significant differences within patients at the different positions of the head of the bed. Utilizing repeated-measures analysis of variance, P values ranged from .34 to .97, well beyond .05. No neurological deterioration occurred.
  
  
  CONCLUSIONS
  In general, elevation of the head of the bed did not cause harmful changes in cerebral blood flow related to vasospasm.
authors.affiliation: The Neuroscience Intensive Care Unit, Duke University Medical Center, Durham, NC, USA.
authors.forename: Patricia A
authors.initials: PA
authors.lastname: Blissitt
authors.forename: Pamela H
authors.initials: PH
authors.lastname: Mitchell
authors.forename: David W
authors.initials: DW
authors.lastname: Newell
authors.forename: Susan L
authors.initials: SL
authors.lastname: Woods
authors.forename: Basia
authors.initials: B
authors.lastname: Belza
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001510:Bed Rest / Q000009:adverse effects; D001783:Blood Flow Velocity; D002560:Cerebrovascular Circulation; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000150:complications* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D011187:Posture; D011446:Prospective Studies; D013345:Subarachnoid Hemorrhage / Q000150:complications* / Q000503:physiopathology; D017585:Ultrasonography, Doppler, Transcranial; D020301:Vasospasm, Intracranial / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology*