Background and Goal of Study:
A number of investigators have identified antiemetic, antinociceptive and anesthetic sparing effects of dexmedetomidine. We aimed to evaluate the impact of the intraoperative dexmedetomidine infusion on the opioid requirement, efficacy, safety and postoperative outcomes in patients undergoing gynecologic cancer surgery.
Materials and Methods: 
120 adult women (20-79 years) undergoing extended abdominal hysterectomy were randomized into 2 groups: 1) control group (CON) n=60, 2) dexmedetomidine group (DEX) n=60. In DEX group the dexmedetomidine infusion has started 15 minutes before induction of anesthesia with the rate of 0,4 μg/kg/h. To assess the speed and quality of recovery, the following were monitored: 1) extubation time; 2) frequency of postoperative nausea or vomiting (PONV); 3) postoperative pain intensity; 4) total rescue dose of analgesics at the first postoperative day. Intraoperatively patients were excluded from the study if they had systolic blood pressure < 80 mmHg for > 5 minutes, heart rate < 40 bpm for > 5 minutes.
Results and Discussion: 
Patients in both groups were comparable on demographic variables. Total dose of fentanyl did not differ between groups. No patients were excluded from the study due to bradycardia or hypotension in CON group, but in DEX group 6 patients were excluded (p=0,01). Mean arterial blood pressure during anesthesia was lower in DEX group versus CON group after endotracheal intubation (p<0,01), after laparotomy (p=0,02) and at the end of surgery (p<0,01). Perioperative heart rate was also decreased in DEX group during endotracheal intubation (p<0,01) , after laparotomy (p<0,01) and at the end of operation (p<0,01). Extubation time did not differ between groups.  The frequency of PONV was lower in DEX group versus CON group (9,3% and 25%, respectively p=0,027).  There were no differences in the postoperative pain intensity.
Conclusion(s): 
Intraoperative use of dexmedetomidine did not impact on extubation time, opioids requirement and postoperative pain intensity but significantly reduced the frequency of PONV. Dexmedetomidine decreased hemodynamic parameters during surgery and increased the risk of significant intraoperative hypotension and bradycardia.

04 / Dexmedetomidine as adjuvant to anesthesia a prospective, randomized trial.