Effects of spontaneous breathing anesthesia on postoperative cognitive dysfunction in elderly patients: a narrative review

Postoperative cognitive dysfunction (POCD) is a common and severe central nervous system complication following anesthesia in elderly patients, significantly increasing their medical burden and reducing quality of life. Conventional endotracheal intubation under general anesthesia may be a potential risk factor, while the associated effects of spontaneous-breathing anesthesia remain inconclusive. This paper elucidates the pathophysiological mechanisms of POCD, including neuroinflammatory cascades, cerebral oxygen metabolism imbalance, blood-brain barrier disruption, and the unique vulnerability of elderly brain tissue. It also analyzes the neuroprotective properties of spontaneous-breathing anesthesia, which optimizes cerebral oxygen supply-demand balance, reduces systemic and central inflammation, and modulates hypothalamic-pituitary-adrenal axis stress responses-demonstrating distinct mechanisms from conventional endotracheal intubation anesthesia. Existing clinical evidence indicates its cognitive protective effects in elderly patients during certain surgeries, though heterogeneity in outcomes across procedure types and methodological limitations in studies persist. Furthermore, this paper outlines key perioperative management points for this anesthetic technique, addresses related controversies, and identifies future research directions such as multimodal monitoring and individualized protocols, providing crucial guidance for perioperative brain health management in elderly patients.