Abstract: AIM: To observe the effects of dexmedetomidine on severity of emergence pain and agitation in children undergoing adenoidectomy. METHODS: 88 patients scheduled for adenoidectomy, ages 4 to 12 years, were enrolled and randomly allocated into control group(n=44, group C) and dexmedetomidine group(n=44, group D).Group C were received intravenous fentanyl bolus 2 g/kg after anesthesia induction with sevoflurane ,whereas in group D were received intravenous dexmedetomidine bolus 1 g/kg over 10 minutes , followed by 0.5 g·kg^-1·h. Fentanyl bolus 1 g/kg was administered to patients in both groups in the presence of an increase in heart rate or systolic blood pressure 30% above precision values that continued for 3 minutes. Pain severity was evaluated and recorded in the postanesthesia care unit on arrival, at 5 minutes ,at 15minutes ,then every 15 minutes for 90 minutes. Emergence agitation was assessed using scale exclusive for child. Fentanyl bolus 0.5 g/kg was given for pain(score above 4) or severe agitation lasting for more than 3 minutes. RESULTS: Atropine and ephedrine were not used in both groups in an attempt to control bradycardia and hypotension. As for heart rate , there was lower rate in group D than that in group C, but no statistical significance was observed in systolic blood pressure between two groups. Time of spontaneous awake and endotracheal extubation were significantly shorter than those in group C(P<0.05,P<0.01). The amount of salvage fentanyl use during peri-operation and in post-anesthetic care unit in group D were lower than that in group C(P<0.01). The frequency of severe emergence agitation on arrival in the post-anesthetic care unit(0 min) was 18% in group D and 47% in group C (P<0.01); at 5 minutes and at 15 minutes, it was lower in group D. The duration of agitation on the scale was statistically lower in group D. In group D, 15% of patients and 42% in group C had an episode of pulse oximetry below 95% (P<0.01) . CONCLUSION: The incidence and duration of severe emergence agitation was lower with fewer patients having desaturation occurrence. An intraoperative infusion of dexmedetomidine combined with inhalation anesthetics provided satisfactory perioperative conditions for adenoidectomy without adverse hemodynamic effects.

Key words: Dexmedetomidine, Pain, Agitation