This prospective cohort study examined 102 adults undergoing first-time isolated on-pump CABG and compared three membrane oxygenators: Capiox FX25, Inspire 8, and Inspire 8F. The Capiox FX25 showed the lowest arterial gaseous microemboli volume and the best volume reduction, while postoperative delirium occurred in 29.4% overall and was least frequent with Capiox FX25. The findings suggest oxygenator choice may influence neurocognitive outcomes after cardiac surgery.