Effect of Intraoperative Dexmedetomidine Use on Postoperative Delirium in the Elderly After Laryngectomy: A Randomized Controlled Clinical Trial

Purpose: To examine whether intraoperative dexmedetomidine reduces postoperative delirium (POD) in elderly patients who underwent a laryngectomy.Methods: Patients were randomly assigned to receive dexmedetomidine or a saline placebo infused during surgery. The study period was July 2020 to January 2022. Participants were elderly individuals (>= 65 years) who underwent a laryngectomy. Immediately after induction of anesthesia, a 0.5 mu g.kg(-1) bolus of study solution was administered for 10 min, followed by a maintenance infusion of 0.2 mu g.kg(-1).hr(-1) until the end of surgery. Patients were assessed daily for POD (primary outcome). Plasma inflammatory factors were measured at baseline, on the first postoperative day, and on the third postoperative day.Results: In total, 304 male patients were randomized; 299 patients [median (interquartile range) age, 69.0 (67.0-73.0) years] completed in-hospital delirium assessments. There was no difference in the incidence of POD between the dexmedetomidine and control groups (21.3% [32 of 150] vs 24.2% [36 of 149], P=0.560). However, dexmedetomidine reduced POD in patients with laryngeal cancer and a higher tumor stage (21.6% vs 38.5%; OR, 0.441; 95% CI, 0.209-0.979; P=0.039). Dexmedetomidine reduced levels of C-reactive protein (CRP) (P=0.0056) and interleukin 6 (IL-6) (P<0.001) on the first and third postoperative days, respectively. More patients had intraoperative hypotension in the dexmedetomidine group (29.3% [44 of 150] vs 17.4% [26 of 149], P=0.015).Conclusion: Intraoperative dexmedetomidine administration did not prevent POD in patients with laryngeal cancer. Dexmedetomidine reduced serum CRP and IL-6 levels postoperatively but caused a higher occurrence of intraoperative hypotension in elderly patients after a laryngectomy.