Flat-head positioning increases cerebral blood flow in anterior circulation acute ischemic stroke. A cluster randomized phase IIb trial

Int J Stroke. 2018 Aug;13(6):600-611. doi: 10.1177/1747493017711943. Epub 2017 Jun 5.


Background Whether lying-flat improves blood flow in patients with acute ischemic stroke is unknown. Our aim was to investigate if lying-flat "changes" cerebral blood flow velocities assessed by transcranial Doppler in acute ischemic stroke patients. Methods In a multicenter cluster clinical trial, we randomly assigned patients within 12 h from onset of a neurological deficit due to cerebral ischemia of the anterior circulation to lying-flat or upright head positioning. The primary outcome was a change of 8 cm/s or more in mean cerebral blood flow velocities on transcranial Doppler to the middle cerebral artery at 1 and 24 h post-randomization, adjusted for imbalance in baseline variables. Secondary outcomes included serious adverse events and physical functioning at 90 days. Results Ninety-four of 304 patients screened were recruited. The primary outcome occurred in 11 (26%) of 43 patients in the lying-flat group and in 6 (12%) of 51 in the upright group at 1 h (adjusted odds ratio, 3.81; 95% CI, 1.07 to 13.54), and in 23 (53%) and 18 (36%) patients in these respective groups at 24 h (adjusted odds ratio, 3.04; 95% CI, 1.08 to 8.53). There were no between-group differences in serious adverse events, including pneumonia, heart failure or mortality, nor in functional outcome at 3 months (adjusted common odds ratio, 1.38; 95% CI 0.64 to 3.00). Conclusion The lying-flat head position was associated with a significant increase in cerebral blood flow velocities at one and 24 h within the ipsilateral hemisphere of anterior circulation acute ischemic stroke, without serious safety concerns. Clinical trial registration-URL: http://www.clinicaltrials.gov . Unique identifier: NCT01706094.

Keywords: Ischemic stroke; blood flow velocities; head position; middle cerebral artery; pilot trial; transcranial Doppler.

Publication types

  • Clinical Trial, Phase II
  • Multicenter Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Blood Flow Velocity
  • Brain Ischemia / diagnosis*
  • Brain Ischemia / mortality
  • Cerebrovascular Circulation
  • Female
  • Head / blood supply*
  • Humans
  • Male
  • Middle Aged
  • Middle Cerebral Artery / physiology*
  • Patient Positioning / methods*
  • Stroke / diagnosis*
  • Stroke / mortality
  • Survival Analysis
  • Ultrasonography, Doppler, Transcranial / methods*

Associated data

  • ClinicalTrials.gov/NCT01706094