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Critical Care and Emergency Medicine

The SOS Pilot Study: A RCT of Routine Oxygen Supplementation Early after Acute Stroke—Effect on Recovery of Neurological Function at One Week
Published: Thursday, May 19, 2011
Author: Christine Roffe et al.

by Christine Roffe, Khalid Ali, Anushka Warusevitane, Sheila Sills, Sarah Pountain, Martin Allen, John Hodsoll, Frank Lally, Peter Jones, Peter Crome


Patients with a clinical diagnosis of acute stroke were recruited within 24 h of hospital admission between October 2004 and April 2008. Participants were randomized to oxygen via nasal cannulae (72 h) or control (room air, oxygen given only if clinically indicated). Clinical outcomes were assessed by research team members at 1 week. Baseline data for oxygen (n?=?148) and control (n?=?141) did not differ between groups.


The median (interquartile range) National Institutes of Health Stroke Scale (NIHSS) score for the groups at baseline was 6 (7) and 5 (7) respectively. The median Nocturnal Oxygen Saturation during treatment was 1.4% (0.3) higher in the oxygen than in the control group (p<0.001) during the intervention. At 1 week, the median NIHSS score had reduced by 2 (3) in the oxygen and by 1 (2) in the control group. 31% of participants in the oxygen group and 14% in the control group had an improvement of =4 NIHSS points at 1 week doubling the odds of improvement in the oxygen group (OR: 2.9).


Our data show that routine oxygen supplementation started within 24 hours of hospital admission with acute stroke led to a small, but statistically significant, improvement in neurological recovery at 1 week. However, the difference in NIHSS improvement may be due to baseline imbalance in stroke severity between the two groups and needs to be confirmed in a larger study and linked to longer-term clinical outcome.

Trial Registration ISRCTN12362720; European Clinical Trials Database 2004-001866-41