Dexmedetomidine-based opioid-sparing anesthesia in video-assisted thoracoscopic surgery: a randomized controlled trial

Dexmedetomidine has increasingly been incorporated into opioid-sparing anesthetic strategies during video-assisted thoracoscopic surgery (VATS) because of its analgesic properties and minimal respiratory depression. However, dexmedetomidine remains associated with dose-related hemodynamic adverse effects, particularly bradycardia and hypotension. We evaluated whether a reduced-dose dexmedetomidine regimen decreases intraoperative opioid requirements while maintaining acceptable hemodynamic safety during VATS. In this prospective randomized controlled trial, 68 patients undergoing VATS were randomly assigned to either a dexmedetomidine group or a control group (34 patients each). The dexmedetomidine group received a loading dose of 0.5 µg/kg followed by continuous infusion at 0.5 µg/kg/h during surgery. The control group received conventional fentanyl-based anesthesia. The primary outcome was maintenance-phase rescue fentanyl consumption. Secondary outcomes included postoperative pain scores, postoperative nausea and vomiting (PONV), postoperative respiratory complications, and perioperative safety outcomes. Maintenance-phase rescue fentanyl consumption was significantly lower in the dexmedetomidine group than in the control group (18.7 vs. 33.2 µg, P = 0.009). Postoperative pain scores, rescue analgesic requirements, PONV, and respiratory complications were comparable between groups. However, the dexmedetomidine group demonstrated a higher incidence of intraoperative bradycardia (23.5% vs. 0%, P = 0.005) and postoperative hypotension during PACU stay (23.5% vs. 2.9%, P = 0.027). These hemodynamic events were transient and responsive to pharmacologic intervention. Dexmedetomidine-based opioid-sparing anesthesia reduced maintenance-phase rescue fentanyl administration during VATS. However, the reduction was modest, was not associated with clear postoperative benefits, and was accompanied by increased bradycardia and hypotension. ClinicalTrials.gov (NCT05431322), registered on 14 June 2022. Available at https://clinicaltrials.gov/study/NCT05431322 .