Study: NCT02412150

Intervention type: PROCEDURE
Group type: PLACEBO_COMPARATOR
Intervention: Thyroidectomy
Description: The aim of this study is evaluation of effect of dexmedetomidine on emergence response and postoperative outcome after thyroidectomy

Intervention type: OTHER
Group type: EXPERIMENTAL
Intervention: Vital signs
Description: Systolic blood pressure, diastolic blood pressure, mean arterial pressure, and heart rate are measured before infusion of testing drugs, after infusion of them (5 min, 10 min, and 15 min), during extubation (0 min and 5 min after extubation), and at recovery room.~And the complications such as hypotension, hypertension, bradycardia, tachycardia, and desaturation after infusion of testing drugs are observed.

Intervention type: OTHER
Group type: PLACEBO_COMPARATOR
Intervention: Vital signs
Description: Systolic blood pressure, diastolic blood pressure, mean arterial pressure, and heart rate are measured before infusion of testing drugs, after infusion of them (5 min, 10 min, and 15 min), during extubation (0 min and 5 min after extubation), and at recovery room.~And the complications such as hypotension, hypertension, bradycardia, tachycardia, and desaturation after infusion of testing drugs are observed.

Intervention type: BEHAVIORAL
Group type: EXPERIMENTAL
Intervention: Cough reflex
Description: During recovery from anesthesia at operation room, cough reflex is measured and rated. \[Grade 0, no cough; Grade 1, single cough with mild severity; Grade 2, cough persistence less than 5 s with moderate severity; Grade 3, severe, persistent cough for more than 5 s (bucking)\]

Intervention type: BEHAVIORAL
Group type: PLACEBO_COMPARATOR
Intervention: Cough reflex
Description: During recovery from anesthesia at operation room, cough reflex is measured and rated. \[Grade 0, no cough; Grade 1, single cough with mild severity; Grade 2, cough persistence less than 5 s with moderate severity; Grade 3, severe, persistent cough for more than 5 s (bucking)\]

Intervention type: BEHAVIORAL
Group type: EXPERIMENTAL
Intervention: Ramsay Sedation Scale
Description: When the patient has fully awaken and transferred to the recovery room, Ramsay Sedation Scale is measured.~1. Awake Patient anxious and agitated or restless or both!~2. Patient cooperative, oriented and tranquil!~3. Patient responds to commands only!~4. Asleep A brisk response to a light glabellar tap or loud auditory stimulus!~5. A sluggish response to a light glabellar tap or loud auditory stimulus!~6. No response to a light glabellar tap or loud auditory stimulus

Intervention type: BEHAVIORAL
Group type: PLACEBO_COMPARATOR
Intervention: Ramsay Sedation Scale
Description: When the patient has fully awaken and transferred to the recovery room, Ramsay Sedation Scale is measured.~1. Awake Patient anxious and agitated or restless or both!~2. Patient cooperative, oriented and tranquil!~3. Patient responds to commands only!~4. Asleep A brisk response to a light glabellar tap or loud auditory stimulus!~5. A sluggish response to a light glabellar tap or loud auditory stimulus!~6. No response to a light glabellar tap or loud auditory stimulus

Intervention type: OTHER
Group type: EXPERIMENTAL
Intervention: Extubation time and Recovery time
Description: The time from discontinuing anesthetic gas to endotracheal extubation is measured.~And the time from the discontinuing of anesthetic gas to transferring to the recovery room is also measured.

Intervention type: OTHER
Group type: PLACEBO_COMPARATOR
Intervention: Extubation time and Recovery time
Description: The time from discontinuing anesthetic gas to endotracheal extubation is measured.~And the time from the discontinuing of anesthetic gas to transferring to the recovery room is also measured.

Intervention type: BEHAVIORAL
Group type: EXPERIMENTAL
Intervention: Visual analogue scale
Description: The severity of pain after surgery is measured by VAS (at recovery room, POD 1, POD 2, and POD 3)

Intervention type: BEHAVIORAL
Group type: PLACEBO_COMPARATOR
Intervention: Visual analogue scale
Description: The severity of pain after surgery is measured by VAS (at recovery room, POD 1, POD 2, and POD 3)

Intervention type: OTHER
Group type: EXPERIMENTAL
Intervention: Postoperative bleeding
Description: The amount of postoperative bleeding which is collected in the barovac is measured.

Intervention type: OTHER
Group type: PLACEBO_COMPARATOR
Intervention: Postoperative bleeding
Description: The amount of postoperative bleeding which is collected in the barovac is measured.

Intervention type: OTHER
Group type: EXPERIMENTAL
Intervention: Postoperative complications
Description: Postoperative complications after thyroidectomy such as hoarseness and hematoma, and reoperation due to such complication is observed.

Intervention type: OTHER
Group type: PLACEBO_COMPARATOR
Intervention: Postoperative complications
Description: Postoperative complications after thyroidectomy such as hoarseness and hematoma, and reoperation due to such complication is observed.

Intervention type: OTHER
Group type: EXPERIMENTAL
Intervention: Time to remove drainage and duration of hospital staying
Description: The time from the end of surgery to remove drainage is measured. And the duration of hospital staying is measured.

Intervention type: OTHER
Group type: PLACEBO_COMPARATOR
Intervention: Time to remove drainage and duration of hospital staying
Description: The time from the end of surgery to remove drainage is measured. And the duration of hospital staying is measured.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Dexmedetomidine
Description: Dexmedetomidine has started infusion for 15 min (rate of 0.6 ug/kg/hr) before end of surgery as experimental intervention

Intervention type: DRUG
Group type: PLACEBO_COMPARATOR
Intervention: Normal saline
Description: Normal saline has started infusion for 15 min (as same rate of dexmedetomidine) before end of surgery as control intervention