The effect of fentanyl and clonidine on early postoperative negative behavior in children: a double-blind placebo controlled trial.

Background: Early negative postoperative behavior (e-PONB) is common in children and manifests itself as emergence agitation (EA), emergence delirium (ED), and pain. The objective of this prospective double blind, randomized, placebo-controlled trial was to determine whether IV clonidine or IV fentanyl prior to surgery modifies e-PONB in children.

Methods: Ninety children scheduled for subumbilical surgery under sevoflurane anesthesia supplemented with regional anesthesia were randomized to either receive IV clonidine 2 mcg·kg(-1) , IV fentanyl 2 mcg·kg(-1) or placebo (IV saline) before surgery. Primary outcome measures were the incidence of EA, ED and pain during the first hour after awakening. Secondary outcome measures were side effects such as nausea and vomiting and delayed discharge from PACU.

Results: Eighty-seven children (n = 29 per group) completed the study. EA was present in 10 children (six clonidine, none fentanyl, and four placebo, P = 0.04) whereas ED was observed in 20 children (nine clonidine, three fentanyl, and eight placebo P = 0.13). Sixteen children who received placebo had a CHIPPS score of ≥4 compared with nine children in fentanyl group and 18 children receiving clonidine (P = 0.04). Ten children receiving fentanyl vomited during the first postoperative day, compared with six children in placebo group and none in clonidine group (P = 0.003). Discharge from PACU was not affected.

Conclusions: IV fentanyl before surgery but not IV clonidine modifies e-PONB in children undergoing lower abdominal surgery under general anesthesia supplemented with regional anesthesia. The use of fentanyl in this population was also associated with reduced pain scores after awakening but with significantly greater incidence of PONV.