Effect of sub - anesthetic dose of esketamine on the incidence of postoperative anxiety and depression in patients with thyroid cancer and breast cancer: A prospective, single - center clinical study

This prospective, single-centre interventional trial in China (n=196 planned; 98 per group) is a Phase 0 parallel-group study evaluating whether subanaesthetic esketamine reduces postoperative anxiety and depression in adults undergoing surgery for thyroid cancer or breast cancer. Participants are randomised to receive either an esketamine infusion prepared at 2.5 mg/ml and administered at 0.25 mg/kg/h, or 0.9% normal saline at 0.1 ml/kg/h as the control comparator. The study population includes both sexes aged 18 years and older. The primary outcome is the incidence of postoperative anxiety and depression in both groups within 72 hours after surgery. Secondary outcomes include postoperative quality of recovery, assessed using the QoR-15 at 48 hours, postoperative pain scores at 48 and 72 hours, and healthcare utilisation measures including length of hospital stay and total cost from surgery to discharge. The trial is designed to assess whether perioperative esketamine can improve early psychological and recovery outcomes in patients with cancer surgery.