Effect of Dexmedetomidine on Postoperative Delirium in Frail Elderly Patients Undergoing Surgery for Gastrointestinal Malignancies: A Randomized, Double-Blind, Controlled Study

Objective: To assess whether intraoperative dexmedetomidine infusion reduces the incidence of postoperative delirium (POD) in frail elderly patients undergoing resection for gastrointestinal malignancies. Methods: A total of 302 patients were enrolled and randomized intoreceiving continuous intravenous infusion ofdexmedetomidine or normal saline intraoperatively. The primary outcome was the incidence of POD within 5 days after surgery. The secondary outcomes were the levels of IL-6, CRP, and Tau protein before surgery and on postoperative days 1 and 3, pain scores (at rest and on coughing) and sleep quality scores from postoperative days 1 to day 5. Results: Compared with normal saline group, the incidence of POD within 5 days after surgery was significantly lower in dexmedetomidine group (13.8% vs. 22.9%, P = 0.048). The level of CRP on postoperative day 1 was lower in dexmedetomidine group ( P = 0.030). The levels of Tau protein were lower on days 1 and 3 ( P = 0.013 and P = 0.032, respectively). In addition, the dexmedetomidine group showed lower postoperative NRS pain scores at rest on day 3 ( P = 0.022) and during cough on day 2 ( P = 0.031), as well as better postoperative sleep quality on days 1, 2, and 4 ( P = 0.040, P = 0.005, and P = 0.018, respectively). Conclusion: In frail elderly patients undergoing surgery for gastrointestinal malignancies, intraoperative dexmedetomidine infusion might reduce the incidence of POD within 5 days after surgery. Trail registration: http://www.chictr.org.cn/index.aspx, NO. ChiCTR2400092665 (Registration date: November 21, 2024, supplementary registration)