4.2 Head Positioning 4.2 Head Positioning COR LOE New, Revised, or Unchanged The benefit of flat-head positioning early after hospitalization for stroke is uncertain. IIb B-R New recommendation. Only 1 sizable trial has evaluated the effect on functional outcomes of flat versus elevated head position after a stroke. HeadPoST (Head Positioning in Acute Stroke Trial) was a large international, cluster-randomized, crossover open- label trial that enrolled any patient hospitalized for stroke (including ICHs) admitted to the hospital to flat-head (0 ) or elevated head ( 30 ) maintained for 24 hours after randomization.240 Distribution of mRS scores at 90 days did not differ between the groups (OR, 1.01 [95% CI, 0.92 1.10]; P=0.84). Patients in the flat-head position group were less often able to maintain the assigned head position for 24 hours, but rates of pneumonia did not differ between the 2 groups. However, this pragmatic trial has been criticized because of various limitations.241 HeadPoST enrolled predominantly patients with minor strokes (median NIHSS score 4) who would be less likely to benefit from increased perfusion compared with patients with more severe strokes and large artery occlusions. In addition, the initiation of the intervention was very delayed (median, 14 hours), potentially missing the window in which head positioning could have made a difference. Several small studies have shown that the lying-flat position may improve cerebral perfusion in patients with AIS caused by a large artery occlusion when the intervention is initiated early after stroke onset.241,242 Thus, there is a rationale for further research focused on this specific cohort of patients. See Table LV in online Data Supplement 1. 4.3. Supplemental Oxygen Note: Recommendations in this section are repeated from Section 3.1 because they apply to in-hospital management as well. 4.3. 