Qing-Yu Tao,1,* Dong Liu,1,* Shi-Jie Wang,2,* Xu Wang,1 Rui-Ning Ouyang,1 Jing-Yi Niu,1 Rende Ning,2 Jun-Ma Yu1 

1Department of Anaesthesiology, The Third Affiliated Hospital of Anhui Medical University (The First People’s Hospital of Hefei), Hefei, Anhui, 230061, People’s Republic of China; 2Department of Orthopaedics, The Third Affiliated Hospital of Anhui Medical University (The First People’s Hospital of Hefei), Hefei, Anhui, 230061, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Jun-Ma Yu, Department of Anaesthesiology, The Third Affiliated Hospital of Anhui Medical University (The First People’s Hospital of Hefei), 390 huaihe Road, Hefei, Anhui, 230061, People’s Republic of China, Tel +8655162183386, Email majuny163@163.com Rende Ning, Department of Orthopaedics, The Third Affiliated Hospital of Anhui Medical University (The First People’s Hospital of Hefei), 390 huaihe Road, Hefei, Anhui, 230061, People’s Republic of China, Tel +8655162189112, Email nrd192@qq.com

Background: Postoperative cognitive dysfunction (POCD) is a common complication after surgery in elderly patients, and its prevalence can be up to 25.6% at one week after noncardiac surgery. This study mainly evaluates the combined effects of esketamine and dexmedetomidine on the incidence of POCD in elderly patients undergoing lumbar spine surgery and explores the underlying mechanisms.
Methods: A total of 162 elderly patients undergoing lumbar spine surgery were randomized into three groups: esketamine combined with dexmedetomidine group (ED group), esketamine group (E group), and dexmedetomidine group (D group). Primary outcome measures included the incidence of POCD on the first postoperative day. Secondary outcomes included the incidence of POCD on the third postoperative day, first postoperative day serum levels of neuron-specific enolase (NSE) and calcium-binding protein β (S100β), patient visual analog scale (VAS) scores at 2, 24, and 48 hours postoperatively, and the incidence of adverse events.
Results: The incidence of POCD on the first postoperative day was significantly lower in the ED group compared to the E group (P = 0.017), with no significant differences when compared to the D group (P = 0.064). The levels of serum NSE in patients in the ED group on the first postoperative day were significantly lower than those in E group and D group (ED group vs E group, P = 0.028; ED group vs D group, P = 0.048). The results for the S100β were similar to those for the NSE (ED group vs E group, P = 0.005; ED group vs D group, P = 0.011).
Conclusion: The combination of esketamine and dexmedetomidine effectively reduces the incidence of POCD on the first postoperative day in elderly patients undergoing lumbar spine surgery.

Keywords: esketamine, dexmedetomidine, postoperative cognitive dysfunction, neuroinflammatory