Intraoperative Dexmedetomidine and Postoperative Delirium After Head and Neck Cancer Surgery with Free-Flap Reconstruction: A Secondary Analysis of a Randomized Placebo-Controlled Trial

Abstract

Background Postoperative delirium is common after major head and neck cancer surgery. We investigated whether intraoperative dexmedetomidine infusion was associated with a lower incidence of postoperative delirium in patients undergoing head and neck cancer surgery requiring free-flap reconstruction. Methods This was a delirium-focused secondary analysis of a single-centre, randomized, double-blind, placebo-controlled trial. Adult patients with head and neck cancer scheduled for elective surgery requiring free-flap reconstruction under general anaesthesia were randomly assigned to receive intraoperative dexmedetomidine infusion at 0.3 μg kg−1h−1 until 1 h before the end of surgery; subjects in the placebo group were given comparable volumes of normal saline. The primary outcome was the incidence of delirium during the first 5 postoperative days, assessed once daily using the Confusion Assessment Method for the Intensive Care Unit (CAM-ICU) or the 3-Minute Diagnostic Confusion Assessment Method (3D-CAM). Results There was less delirium during the initial 5 postoperative days in patients assigned to dexmedetomidine (14.9%, 7 of 47 patients) than in those given placebo (34.7%, 17 of 49 patients). Dexmedetomidine was associated with lower odds of postoperative delirium after adjustment for age, preoperative Mini-Mental State Examination score, and operative time (adjusted odds ratio 0.31, 95% confidence interval 0.10–0.92; p = 0.036). Postoperative pain and early sleep outcomes were improved by dexmedetomidine. Haemodynamic adverse events and postoperative complications did not differ significantly between groups. Conclusion In patients undergoing head and neck cancer surgery with free-flap reconstruction, intraoperative dexmedetomidine infusion was associated with a lower incidence of postoperative delirium during the first 5 postoperative days, without an apparent increase in perioperative adverse events. Clinical Trial Registration ChiCTR2300067376.