Double-blind, placebo-controlled randomised trial (n=1670) testing low-dose intraoperative and postoperative esketamine versus placebo to prevent postoperative delirium in high-risk elderly patients undergoing major non-cardiac surgery.
Postoperative delirium is a common, acute neurocognitive disorder among older surgical patients and is associated with worse short- and long-term outcomes; this multicentre trial tests whether intraoperative and postoperative low-dose esketamine reduces delirium incidence in high‑risk elderly patients undergoing major non‑cardiac surgery.
Esketamine has anti‑inflammatory and neuroprotective effects; the trial administers a 0.2 mg/kg loading dose after induction with 0.1 mg/kg/h maintenance until 40 minutes before surgery end, plus postoperative PCIA containing esketamine and sufentanil, compared with matched saline infusion and sufentanil‑only PCIA; outcomes include delirium incidence and cognitive and safety measures.
IV intraoperative loading and maintenance esketamine infusion plus postoperative esketamine-containing PCIA for analgesia.
Loading 0.2 mg/kg after induction (1.2 ml/kg/h over 10 min at 1 mg/ml), then maintenance 0.1 mg/kg/h until 40 min before end of surgery; postoperative PCIA: esketamine 50 mg + sufentanil 200 μg in 200 ml, background 2 ml/h, bolus 2 ml, lockout 15 min.
Normal saline infusion intraoperatively and standard sufentanil-only PCIA postoperatively (placebo comparator).
Normal saline infusion matching esketamine rates intraoperatively; postoperative PCIA contains sufentanil 200 μg in 200 ml, background 2 ml/h, bolus 2 ml, lockout 15 min.