BACKGROUND: Emergence agitation (EA) is a common postoperative problem in young 
children who have received sevoflurane and isoflurane for general anesthesia. 
This randomized, double-blinded study evaluated the efficacy of intraoperative 
clonidine in reducing EA, and describes its recovery profile.
METHODS: With Institutional Review Board approval and informed consent, children 
undergoing brief, minimally painful procedures were studied. All children 
received preemptive analgesia with acetaminophen and ketorolac, sevoflurane for 
induction, and isoflurane for maintenance of anesthesia. Children received 
either 2 microg.kg(-1) clonidine or placebo intravenously (i.v.) following 
induction of anesthesia. Children were observed postoperatively for behavior and 
side effects, and their parents were telephoned the next day to determine 
postdischarge recovery characteristics.
RESULTS: One hundred and twenty children were included in this study: 59 of whom 
received clonidine, and 61 placebo; 41% of those in the placebo group exhibited 
moderate-severe EA compared with only 22% of those in the clonidine group (P < 
0.03). Compared with those who received placebo, children who received clonidine 
awakened more slowly (22 min vs 14 min), had a longer postanesthesia care unit 
stay (57 min vs 46 min), and experienced sleepiness more frequently after 
discharge (75% vs 39%; all comparisons significant at P < 0.03). There were no 
adverse cardiorespiratory events in either group.
CONCLUSIONS: Findings demonstrate that i.v. clonidine administered after 
induction of anesthesia significantly reduces the incidence of EA in young 
children, but is associated with sleepiness postoperatively.