Comparison of the effects of dexmedetomidine, ketamine, and placebo on emergence agitation after strabismus surgery in children

Children undergoing strabismus surgery under sevoflurane anesthesia often experience emergence agitation (EA) and postoperative vomiting (POV). This study compared the effects of intraoperative dexmedetomidine, ketamine, and placebo on postoperative EA and POV. Eighty-four children (aged two to seven years) undergoing elective strabismus surgery under sevoflurane anesthesia were randomly assigned to one of three groups (n = 28 each). Intraoperatively, the placebo, dexmedetomidine, and ketamine groups received normal saline, dexmedetomidine 1 mu g center dot kg(-1) iv plus a 1 mu g center dot kg(-1)center dot hr(-1) infusion, and ketamine 1 mg center dot kg(-1) iv plus a 1 mg center dot kg(-1)center dot hr(-1) infusion, respectively. Agitation scores (Pediatric Anesthesia Emergence Delirium [PAED] scale) and POV were assessed in the postanesthetic care unit (PACU) and for 24 hr on the ward. Pain scores and times to laryngeal mask airway (LMA (TM)) removal, resumption of mental orientation, and discharge from the PACU were also assessed. Seventy-eight children completed the study. Peak PAED scores for EA were lower in the dexmedetomidine (P < 0.001) and ketamine (P = 0.002) groups than in the placebo group. Incidence of POV was lower in the dexmedetomidine group (15%) than in the ketamine (44%; P = 0.02) or placebo (45.8%; P = 0.02) groups. Pain scores on the ward were lower in the dexmedetomidine (P < 0.001) and ketamine (P < 0.001) groups than in the placebo group. Time to LMA removal was similar in all groups. Time for resumption of mental orientation and time to discharge from PACU were longer in the dexmedetomidine and ketamine groups than in the placebo group. Dexmedetomidine and ketamine appear to prevent postoperative agitation and pain after sevoflurane anesthesia for pediatric strabismus surgery. Dexmedetomidine also prevents POV.