Cerebral blood flow velocity changes during upright positioning in bed after acute stroke: an observational study.
OBJECTIVE
National guidelines recommend mobilisation in bed as early as possible after acute stroke. Little is known about the influence of upright positioning on real-time cerebral flow variables in patients with stroke. We aimed to assess whether cerebral blood flow velocity (CBFV) changes significantly after upright positioning in bed in the acute stroke phase.


METHODS
Observational study.


METHODS
47 patients with acute ischaemic stroke measured in the subacute phase after symptom onset and 20 healthy controls.


METHODS
We recorded postural changes in bilateral transcranial Doppler (primary outcome) and simultaneously recorded near-infrared spectroscopy, end-tidal CO2, non-invasive blood pressure data and changes in neurological status (secondary outcomes).


METHODS
Postures included the supine, half sitting (45°), sitting (70°) and Trendelenburg (-15°) positions. Using multilevel analyses, we compared postural changes between hemispheres, outcome groups (using modified Rankin Scale) as well as between patients and healthy controls.


RESULTS
The mean patient age was 62±15 years and median National Institute of Health Stroke Scale score on admission was 7 (IQR 5-14). Mean proportional CBFV changes on sitting were not significantly different between healthy controls and affected hemispheres in patients with stroke. No significant differences were found between affected and unaffected stroke hemispheres and between patients with unfavourable and favourable outcomes. During upright positioning, no neurological worsening or improvement was observed in any of the patients.


CONCLUSIONS
No indications were found that upright positioning in bed in mild to moderately affected patients with stroke compromises flow and (frontal)oxygenation significantly during the subacute phase of stroke. Supine or Trendelenburg positioning does not seem to augment real-time flow variables.
Department of Neurology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands.
Marcel J
MJ
Aries
Jan Willem
JW
Elting
Roy
R
Stewart
Jacques
J
De Keyser
Berry
B
Kremer
Patrick
P
Vroomen