title: Cerebral blood flow dynamics and head-of-bed changes in the setting of subarachnoid hemorrhage.
abstract: Head-of-bed (HOB) elevation is usually restricted in patients with aneurysmal subarachnoid hemorrhage (SAH). The goal of this study is to correlate HOB changes (0° and 90°) with cerebral blood flow using transcranial Doppler (TCD) and thermal diffusion probe in SAH patients. Thirteen patients with SAH were prospectively enrolled in the study. Eight patients underwent placement of a thermal diffusion probe for regional CBF measurement. CBF values were measured with the patients in flat (0°) and upright sitting positions (90°) at days 3, 7, and 10. The average increase in blood flow velocity when changing HOB from 0° to 90° was 7.8% on day 3, 0.1% on day 7, and 13.1% on day 10. The middle cerebral artery had the least changes in velocity. The average regional CBF measurement was 22.7 ± 0.3 mL/100 g/min in the supine position and 23.6 ± 9.1 mg/100 g/min in the sitting position. The changes were not statistically significant. None of the patients developed clinical cerebral vasospasm. Changing HOB position in the setting of SAH did not significantly affect cerebral or regional blood flow. These data suggest that early mobilization should be considered given the detrimental effects of prolonged bed rest.
authors.affiliation: Department of Neurosurgery, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, JCP 1616, Iowa City, IA 52242, USA.
authors.forename: David K
authors.initials: DK
authors.lastname: Kung
authors.affiliation: Department of Neurosurgery, Thomas Jefferson University and Jefferson Hospital for Neuroscience, Philadelphia, PA, USA.
authors.forename: Nohra
authors.initials: N
authors.lastname: Chalouhi
authors.affiliation: Department of Neurosurgery, Thomas Jefferson University and Jefferson Hospital for Neuroscience, Philadelphia, PA, USA.
authors.forename: Pascal M
authors.initials: PM
authors.lastname: Jabbour
authors.affiliation: Department of Neurological Surgery, University of Virginia School of Medicine, Charlottesville, VA, USA.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Starke
authors.affiliation: Department of Neurosurgery, Thomas Jefferson University and Jefferson Hospital for Neuroscience, Philadelphia, PA, USA.
authors.forename: Aaron S
authors.initials: AS
authors.lastname: Dumont
authors.affiliation: Department of Neurosurgery, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, JCP 1616, Iowa City, IA 52242, USA.
authors.forename: H Richard
authors.initials: HR
authors.lastname: Winn
authors.affiliation: Department of Neurosurgery, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, JCP 1616, Iowa City, IA 52242, USA.
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Howard
authors.affiliation: Department of Neurosurgery, University of Iowa Hospitals and Clinics, 200 Hawkins Drive, JCP 1616, Iowa City, IA 52242, USA.
authors.forename: David M
authors.initials: DM
authors.lastname: Hasan
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001783:Blood Flow Velocity; D001921:Brain / Q000098:blood supply* / Q000000981:diagnostic imaging / Q000473:pathology; D002560:Cerebrovascular Circulation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000503:physiopathology; D013345:Subarachnoid Hemorrhage / Q000000981:diagnostic imaging / Q000473:pathology* / Q000628:therapy; D014057:Tomography, X-Ray Computed