Efficacy and safety of normobaric hyperoxia as an adjunct to endovascular thrombectomy in acute ischemic stroke: A systematic review and meta-analysis of randomized controlled trials

Abstract

Endovascular thrombectomy (EVT) is the standard of care in acute ischemic stroke (AIS), yet functional outcomes remain suboptimal. Normobaric hyperoxia (NBHO) is a potential neuroprotective strategy. This study is the first systematic review and meta-analysis to assess NBHO as a potential neuroprotective adjunctive to improve outcomes in EVT-treated patients. A comprehensive search of electronic databases, including PubMed, Scopus, Cochrane, and Web of Science, was performed in February 2025. The inclusion criteria targeted randomized controlled trials (RCTs) comparing NBHO and EVT to EVT alone or with sham oxygen therapy. Statistical analyses were performed using RevMan software. Four RCTs comprising 648 patients with AIS due to large vessel occlusion in the anterior circulation were included in the study. For the primary efficacy endpoint of excellent functional outcome, defined as the number of patients who had a Modified Rankin Scale (mRS) score of ≤ 1 at 90 days, the overall odds ratio with a subgroup based on the oxygen delivery duration at 2, 4, and 6 h was in favor of the NBHO group compared to the control (OR = 1.66, 95% CI [1.13, 2.45], P = 0.01, I2 = 0%). The subgroup of 4-hour oxygen delivery duration was the only significant subgroup (OR = 1.6, 95% CI [1.01, 2.51], P = 0.04). Safety outcomes showed no significant differences between the NBHO group and the control group across all reported measures. NBHO as an adjunct to EVT appears to be effective and safe. A 4-hour duration was found to be the most effective. Further RCTs are needed to confirm our results and establish the optimal treatment protocol.