Stroke Oxygen Study

December 8, 2017

Written by Thomas Davis, MD.

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Administering prophylactic low-dose oxygen (2-3L/min) to non-hypoxemic patients with acute stroke did not reduce death or disability at 3 months. 

Why does this matter?
Hypoxemia is common during the first few days after stroke. Continuous monitoring and oxygen supplementation when hypoxic is associated with better outcomes. However, hypoxemia is not always identified—even when continuously monitored. Does prophylactic oxygen administration improve outcomes too?

SOS: Stroke Oxygen Study
This pragmatic RCT randomized 8003 patients 1:1:1 to either continuous oxygen, nocturnal oxygen, or control (oxygen only if identified to be hypoxemic). Patients were enrolled within 24 hours of stroke onset. Oxygen was provided for 72 hours. There was a small but statistically significant increase in lowest oxygen saturation between continuous oxygen and control (95.0% vs 94.1%, p<0.001). However, there was no difference in death or disability at 3 month follow-up. The odds ratio for a better outcome with any prophylactic oxygen versus control was 0.97 (95% CI 0.89-1.05). There were no differences among any subgroups that were most likely to benefit from prophylactic oxygen: more severe stroke, enrolled within 3 hours of stroke onset, lower baseline oxygen saturation, or history of heart failure or lung disease.

Source
Effect of Routine Low-Dose Oxygen Supplementation on Death and Disability in Adults With Acute Stroke: The Stroke Oxygen Study Randomized Clinical Trial.  JAMA. 2017 Sep 26;318(12):1125-1135. doi: 10.1001/jama.2017.11463.

Peer reviewed by Clay Smith, MD.