Dexmedetomidine is an α2 receptor agonist with sedative and analgesic properties. In previous reports, dexmedetomidine improves smoothness of postoperative recovery and reduces intraoperatory imflammatory responses. As patients receiving breast surgeries are especially vulnerable to postoperative nausea/ vomiting, the dosage of narcotics and associated complications were concerned for not only comfortness but also postoperative oral intake and discharge. The invetigators aimed to compare the effects of dexmedetomidine infusion versus placebo on postoperative narcotics requirement, complications, and oral intake.

Dexmedetomidine is an α2 receptor agonist with sedative and analgesic properties. In previous reports, dexmedetomidine improves smoothness of postoperative recovery and reduces intraoperatory imflammatory responses. As patients receiving breast surgeries are especially vulnerable to postoperative nausea/ vomiting, the dosage of narcotics and associated complications were concerned for not only comfortness but also postoperative oral intake and discharge.

The invetigators aimed to compare the effects of dexmedetomidine infusion versus placebo on postoperative narcotics requirement, complications, and oral intake.

The participantss under general anesthesia and aged from 30 to 65 years old will be enrolled. All subjects were randomized into the dexmedetomidine or placebo group. They received placebo (group P, n = 30) or dexmedetomidine (loading dose of 1 μg kg-1 followed by 0.5 μg kg-1 h-1) (group D, n = 30) to the end of surgery.

Data collected included intraoperative and postoperative opioid consumption. Postoperative questionare including PONV, Pain intensity, I-FEED questionnaire. Prospective analysis will be performed on the prospectively collected data.

We expected to examine if intraoperative dexmedetomidine decreases the postoperative opioid consumption and associated complications, and enhances the gastrointestinal recovery and oral intake with narcotic-sparing effect.

Inclusion Criteria:

• Patients who fulfill the criteria of breast cancer under general anesthesia.

Exclusion Criteria:

• Major systemic disease, such as congestive heart failure, liver cirrhosis, end stage renal disease and malignancy.
• Patients who have the risk of difficult ventilation or intubation.
• Pregnant women.
• Coagulopathy.

due to the ethical concern, we did not share our paatients' data.

double blind randomized study