The rapid emergence and recovery from general anesthesia afforded by sevoflurane is associated with a high incidence of emergence agitation in children. Small doses of ketamine reduce the incidence of emergence agitation. This study compared the effects of ketamine 0.25 mg/kg and 0.5 mg/kg on emergence agitation and postoperative pain.

The effects of added intravenous ketamine were evaluated in 93 children, ASA I-II, 2-14 years old, undergoing an adenotonsillectomy. The patients were allocated randomly to one of three groups receiving saline (group C), ketamine 0.25 mg/kg (group K0.25) or ketamine 0.5 mg/kg (group K0.5). The children in each group were administered the study drugs 10 minutes before the end of surgery. The recovery characteristics, including the time to extubation, delivery time from the PACU, postoperative nausea and vomiting, agitation and pain were assessed.

There were no significant differences in the extubation time, delivery time and postoperative nausea and vomiting between the three groups. There were significant differences in modified CHEOPS (Children's Hospital of Eastern Ontario Pain Scale) between the three groups. The incidence of emergence agitation was low in the K0.25 and K0.5 groups compared to the control group. However, there was no significant difference between the K0.25 and K0.5 groups.

There was no significant difference in the incidence of emergence agitation between K0.25 and K0.5 groups. However, K0.5 group showed a lower pain score than K0.25 group.