Normobaric Oxygen Therapy in Acute Stroke: A Systematic Review and Meta-Analysis

Area of Science:

• Neurology
• Critical Care Medicine
• Pharmacology

Background:

• Normobaric oxygen (NBO) presents a potential neuroprotective therapy for acute stroke.
• This systematic review evaluates the efficacy of NBO in improving outcomes for patients experiencing acute stroke.

Approach:

• A systematic review and meta-analysis were conducted, searching MEDLINE, EMBASE, and CENTRAL databases up to December 2020.
• Included were randomized controlled trials of NBO administered within 7 days of stroke onset in normoxic patients without other oxygen indications.
• Data extracted included neurological recovery, functional outcomes, mortality, oxygen saturation, and imaging markers.

Key Points:

• Fifteen publications involving 9,255 participants were analyzed, with one large, low-risk-of-bias study.
• The majority of participants received low-flow oxygen (≤4 L/min) in the sub-acute phase (median 19.3 h post-stroke).
• Meta-analysis revealed no significant effect of NBO on early neurological recovery (NIH Stroke Scale), functional outcome (modified Rankin Scale), or mortality.

Conclusions:

• Current evidence indicates that NBO therapy does not significantly improve early neurological recovery, functional outcomes, or mortality in acute stroke patients.
• The predominant use of low-flow oxygen and delayed administration in the sub-acute phase may limit potential benefits.
• Further research is needed to explore optimal oxygen delivery methods and timing for potential neuroprotection in acute stroke.