Early Oxygenation Levels and Clinical Outcomes in Postendovascular Therapy Ischemic Stroke: An Exploratory Analysis of the RESCUE-RE Registry

BACKGROUND: Studies on oxygenation in acute ischemic stroke (AIS) mainly focus on the prehospital care and during endovascular therapy (EVT). This study aimed to explore the association between arterial oxygenation levels within the first 24 hours of intensive care unit (ICU) admission and neurological recovery, as well as pulmonary complications in AIS patients after EVT. METHODS: We conducted an exploratory analysis of the multicenter RESCUE-RE registry, including 532 AIS patients who underwent EVT at 18 comprehensive stroke centers in China from January 2019 to June 2024. Patients were categorized by arterial blood gas measurements within 24 hours post-ICU admission into hypoxemia (PaO 2 120 mm Hg) groups. The primary outcome was functional independence (modified Rankin Scale [mRS] score 0 to 2) at 90 days. Secondary outcomes included other mRS thresholds, 90-day all-cause mortality, neurological improvement/deterioration, and pulmonary infection incidence. Multivariable regression adjusted for confounders assessed associations between PaO 2 levels and outcomes. RESULTS: Functional independence rates at 90 days did not differ significantly among hypoxemia (26.8%), normoxemia (27.2%), and hyperoxemia (24.5%) groups ( P =0.788). Adjusted analyses showed no significant association between PaO 2 levels and neurological outcomes or mortality. Secondary outcomes, including neurological changes, were also comparable across groups. Notably, normoxemia and hyperoxemia were associated with significantly lower pulmonary infection risk compared with hypoxemia (adjusted ORs: 0.48 to 0.63). CONCLUSIONS: In AIS patients undergoing EVT, early postoperative arterial oxygenation was not associated with 90-day neurological recovery, whereas hypoxemia was associated with pulmonary infection.