Effects of Different Administration Routes of Dexmedetomidine on Postoperative Sleep Quality in Patients Undergoing Thyroidectomy

This randomized controlled trial was conducted to evaluate the effects of different administration routes of dexmedetomidine on postoperative sleep quality in patients undergoing thyroidectomy. A total of 120 patients were randomized into three groups in a 1:1:1 ratio using computer-generated randomization and sealed opaque envelopes.IN-D group: Intranasal dexmedetomidine plus intravenous placebo. Dexmedetomidine 1.0 μg/kg (maximum 100 μg) was administered intranasally via alternating nostrils 30 minutes before surgery, with an equal volume of 0.9% saline infused intravenously.IV-D group: Intravenous dexmedetomidine plus intranasal placebo. A loading dose of dexmedetomidine 0.5 μg/kg was infused intravenously over 10 minutes 30 minutes preoperatively, with an equal volume of 0.9% saline administered intranasally.Control group: Intranasal and intravenous placebo (0.9% saline in both routes).Patients, attending anesthesiologists, and outcome assessors were blinded to group allocation throughout the study. Intraoperative anesthesia management was performed by a separate anesthesiologist not involved in data assessment to maintain blinding. All patients fasted for 6 hours and restricted clear fluids for 2 hours preoperatively. No premedication was administered.Upon arrival in the operating room, standard monitoring was applied, including electrocardiography (ECG), pulse oximetry (SpO₂), and non-invasive blood pressure (NIBP). Invasive arterial cannulation was performed for continuous blood pressure monitoring.General anesthesia was induced with etomidate 0.2 mg/kg, rocuronium 0.6 mg/kg, sufentanil 0.5 μg/kg, and propofol 1.5 mg/kg. After 5 minutes of preoxygenation, tracheal intubation was performed under video laryngoscopy. Mechanical ventilation was initiated with pure oxygen at 2.0 L/min, with tidal volume 6-8 mL/kg, I:E ratio 1:2, and PETCO₂ maintained at 35-45 mmHg. Correct positioning of the neuromonitoring endotracheal tube was verified after intubation.Anesthesia depth was maintained at an entropy index (RE/SE) of 40-60 by adjusting infusions of propofol and remifentanil and the concentration of sevoflurane. Hemodynamic stability was maintained using vasoactive agents (ephedrine, phenylephrine, nitroglycerin) as needed.All anesthetics were stopped at skin closure. Patients were transferred to the post-anesthesia care unit (PACU) immediately after surgery. Tracheal extubation was performed when patients recovered consciousness and adequate spontaneous respiration.