Effect and mechanism of low-dose esketamine on postoperative cognitive function in elderly non-cardiac patients with sleep disturbance

This parallel interventional trial in China (n=240) is assessing whether low-dose esketamine can reduce postoperative cognitive dysfunction in elderly non-cardiac surgical patients with sleep disturbance. Participants aged 65 years and older are allocated to an esketamine group (loading dose 0.25 mg/kg followed by 0.25 mg/kg/h infusion) or a control group receiving an equal volume of 0.9% normal saline. The study is focused on postoperative cognitive dysfunction, with the primary outcome being its incidence after surgery; the specific assessment timepoints are not reported in the available record. Secondary outcomes include haemodynamic stability, postoperative delirium, inflammatory and neural biomarkers (including IL-1β, IL-6, TNF-α, S100-β, HMGB1, RAGE and NfL), anxiety and depression scores, sleep quality, pain scores, depth of anaesthesia, vasoactive drug use, and postoperative nausea and vomiting. No trial phase is specified. The study is being conducted at Anhui No.2 Provincial People's Hospital in China.