Thyroid surgery requires smooth emergence from anesthesia to minimize coughing, hemodynamic fluctuations, and agitation during extubation, which may contribute to postoperative complications such as bleeding or cervical hematoma. Dexmedetomidine, a selective α2-adrenergic receptor agonist, has sedative, analgesic-sparing, and sympatholytic properties that may improve anesthetic stability and recovery quality. This randomized controlled trial aims to evaluate the effectiveness of a continuous perioperative dexmedetomidine regimen initiated at induction of anesthesia and maintained during thyroid surgery. The study will compare dexmedetomidine combined with standard balanced anesthesia versus standard anesthesia alone in terms of anesthetic requirements and emergence quality. The primary hypothesis is that perioperative dexmedetomidine administration reduces anesthetic and opioid requirements and improves emergence quality by decreasing coughing during extubation and hemodynamic responses.
Dexmedetomidine has been widely studied as an anesthetic adjunct due to its sedative and analgesic-sparing effects without significant respiratory depression. Previous randomized trials have demonstrated its ability to reduce coughing during extubation, attenuate sympathetic responses, and improve recovery quality after thyroid surgery. However, most studies have administered dexmedetomidine only during emergence or intraoperatively. This study investigates a comprehensive perioperative dexmedetomidine protocol consisting of: * A loading dose immediately before induction of anesthesia * Continuous infusion during surgery The aim is to assess whether this regimen improves intraoperative anesthetic efficiency and postoperative recovery quality. Patients scheduled for thyroid surgery under general anesthesia will be randomized to receive dexmedetomidine or standard anesthesia without dexmedetomidine. Standardized anesthetic techniques will be used for induction, maintenance, and postoperative care. Outcome measures include anesthetic requirements, opioid consumption, coughing at extubation, emergence agitation, hemodynamic responses, postoperative nausea and vomiting (PONV), and postoperative bleeding complications.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
DOUBLE
Enrollment
100
Dexmedetomidine administered perioperatively as an anesthetic adjunct. A loading dose of 1 µg/kg is infused immediately before induction of anesthesia (in 10 minutes), followed by continuous infusion at 0.5 µg/kg/h during surgery. Depth of anesthesia is monitored using bispectral index (BIS), and volatile anesthetic concentration is titrated to a target BIS range (40-60). Neuromuscular blockade is monitored using train-of-four (TOF) stimulation, and neuromuscular blocking agents are titrated accordingly, with extubation performed after standard neuromuscular recovery criteria are met.
Standardized balanced general anesthesia using intravenous induction with propofol, opioid analgesia, and neuromuscular blockade, followed by maintenance with inhalational anesthetic agents according to institutional practice. Depth of anesthesia is monitored using bispectral index (BIS), and volatile anesthetic concentration is titrated to a target BIS range (40-60). Neuromuscular blockade is monitored using train-of-four (TOF) stimulation, and neuromuscular blocking agents are titrated accordingly, with extubation performed after standard neuromuscular recovery criteria are met.
Center for Anesthesia and Surgical Intensive Care, Bach Mai Hospital
Hanoi, Vietnam
RECRUITINGIncidence and Severity of Coughing During Extubation
Coughing during emergence will be assessed using a standardized cough grading scale: * Grade 0: No cough * Grade 1: Single cough * Grade 2: Cough lasting ≤5 seconds * Grade 3: Sustained cough \>5 seconds or severe coughing The incidence and severity of cough will be recorded.
Time frame: From suctioning of airway secretions until 5 minutes after extubation
Total Intraoperative Anesthetic Requirement
Total dose of anesthetic agents used during maintenance of anesthesia will be recorded, including: Volatile anesthetic concentration (MAC equivalents)
Time frame: During surgery
Total Intraoperative Opioid Consumption
Total dose of fentanyl administered intraoperatively will be recorded.
Time frame: During surgery
Emergence Agitation
Emergence agitation severity will be assessed using Aono's Four-Point Agitation Scale. The scale ranges from 1 to 4, where 1 indicates calm, 2 indicates not calm but easily consoled, 3 indicates moderate agitation or restlessness and not easily calmed, and 4 indicates severe agitation with combative, excited, or disoriented behavior. Higher scores indicate worse emergence agitation.
Time frame: During emergence and within the first 15 minutes in the PACU.
Mean arterial pressure (mmHg)
Mean arterial pressure (mmHg) measured at induction, intubation, surgical incision, end of surgery, extubation, and 10 minutes after extubation.
Time frame: From induction to 10 minutes after extubation.
Heart rate (beats per minute)
Heart rate (beats per minute) measured at induction, intubation, surgical incision, end of surgery, extubation, and 10 minutes after extubation.
Time frame: From induction to 10 minutes after extubation.
Postoperative Pain Intensity
Pain intensity assessed using the Visual Analog Scale for pain, 0-10 cm , where 0 indicates no pain and 10 indicates worst imaginable pain; higher scores indicate worse pain. Assessed at PACU arrival, 1 hour, 6 hours, 12 hours, and 24 hours postoperatively.
Time frame: PACU arrival; 1 hour; 6 hours; 12 hours; and 24 hours postoperatively.
Postoperative Nausea and Vomiting (PONV)
Incidence of nausea or vomiting and requirement for antiemetic therapy will be recorded.
Time frame: Within 24 hours after surgery
Postoperative Recovery Quality
Postoperative quality of recovery will be assessed using the 15-item Quality of Recovery questionnaire (QoR-15). The total score ranges from 0 to 150, with higher scores indicating better postoperative recovery. The questionnaire will be completed 24 hours after surgery.
Time frame: 24 hours after surgery
Postoperative Bleeding or Cervical Hematoma
Any clinically significant bleeding or cervical hematoma requiring intervention will be recorded.
Time frame: Within 24 hours after surgery
Propofol consumption for induction
Propofol consumption for induction guided by BIS
Time frame: During induction
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