A simplest manner to augment cerebral blood flow to irrigate the ischemic penumbra in acute ischemic stroke could be to place the patient in a 'lying flat' rather than upright head position. Given uncertainty over the balance of potential modest benefits and risks, and variability regarding the ideal head position policy for patients with acute ischemic stroke around the world, reliable randomized evidence is required to standardize clinical practice.

The main objectives of this pilot phase clinical trial are to determine the feasibility, safety and potential efficacy of a large-scale cluster randomized clinical trial to assess whether a simple nursing care policy - 'lying flat head position' - provides beneficial effects as compared to the standard upright head position in patients with acute ischemic stroke. The main efficacy outcome of the pilot phase is demonstration of increased mean cerebral blood flow velocity in the flat down compared to the upright head position, as assessed by transcranial Doppler to the medial cerebral arteries of patients with anterior circulation infarction. Secondary efficacy objectives are to demonstrate that the flat down head position improves neurological status at 7 days and disability at 90 days.

Background: Several lines of investigation indicate there to be potential beneficial effects of interventions that augment cerebral blood flow (CBF) to irrigate the ischemic penumbra in acute ischemic stroke. The simplest manner to do this is to place the patient in a 'lying flat' rather than upright head position. However, any potential benefits on the brain may be offset by an increased hazard of aspiration pneumonia or exacerbation of cardiac failure in vulnerable patients. Given uncertainty over the balance of potential modest benefits and risks, and variability regarding the ideal head position policy for patients with acute ischemic stroke around the world, reliable randomized evidence is required to standardize clinical practice.

Aims: The main objectives of this pilot phase clinical trial are to determine the feasibility, safety and potential efficacy of a large-scale cluster randomized clinical trial to assess whether a simple nursing care policy - 'lying flat head position' - provides beneficial effects as compared to the standard upright head position in patients with acute ischemic stroke. The main efficacy outcome of the pilot phase is demonstration of increased mean cerebral blood flow velocity (CBFV) in the lying flat head position compared to the upright head position, as assessed by transcranial Doppler (TCD) to the medial cerebral arteries of patients with anterior circulation infarction. Secondary efficacy objectives are to demonstrate that the lying flat head position improves neurological status at 7 days and disability at 90 days.

Methods: Inclusion criteria include consecutive adult patients with acute ischemic stroke within 12 hours of onset admitted to participating centers. A cluster (month) method of randomization to lying flat or upright head position for 48 hours, stratified by site The primary outcome is change in mean CBFV measured by TCD at 24 hours. Secondary outcomes include proportion of adverse events at 7 days, distribution of NIHSS at 7 days, and distribution of mRS disability scale scores at 90 days. Sample size is 46 clusters of 2 patients totaling approximately 92 patients to detect an increase of 8.31 (CI 95% 4.82-12.0) cm/sec in average CBFV from 30° to 0° head position. This sample size will also allow detection of that difference with 90% power at a 5% significance level, considering an ICC of 0.037.

Inclusion Criteria:

• Age 18 or more years old
• Patients with an acute stroke corresponding to anterior circulation, a CT scan ruling out intracranial hemorrhage, presenting within 12 hours from symptom onset
• NIHSS ≥1
• Susceptible to be tilted down to the flat position or to 30º of the head
• There is uncertainty about the benefit/harm of head position during a minimum of 24 hours.
• Informed consent given

Exclusion Criteria:

• Contraindications to a flat head position (active vomiting, pneumonia, uncontrolled heart failure)
• Concomitant medical illness that would interfere with outcome assessment and follow-up
• Planned decompressive craniectomy or carotid endarterectomy.
• Absence of sonographic temporal window