Effects of Fentanyl Administered Few Minutes Before the End of Surgery on Emergence Delirium Among Children Undergoing Adeno-tonsillectomy: a Randomized Double Blind Placebo Controlled Clinical Trial.

Abstract

Background; Modern volatile, insoluble inhalational anaesthetic agents used in surgery are associated with increased incidence of emergence delirium(ED) in children. Fentanyl prevents ED in high income settings where sevoflurane and desflurane are the predominant anaesthetics. However, in low income settings, halothane and isoflurane are the most frequently used anaesthetics; the effect of Fentanyl on reducing the incidence of ED has not been evaluated. Objectives The study estimated the incidence of ED using watcha scale, the effectiveness and effects of fentanyl administered approximately ten minutes to end of surgery on the incidence of ED, among children undergoing adeno-tonsillectomy under halothane and isoflurane anaesthesia. Methods A randomized double blind placebo controlled clinical trial, in which children aged between 1-12 years undergoing adeno-tonsillectomy under halothane and isoflurane anaesthesia at Kenyatta National Hospital were randomized to either Fentanyl at 1ug/kg or equivalent volume of normal saline in blocks. Fentanyl or normal saline was administered approximately ten minutes to the end of surgery. Children were observed for a period of 30 minutes after surgery in the recovery room. The main outcome was the proportion of children experiencing ED. We conducted intent to treat analysis and compared incidence of ED using logistic regression to obtain odds ratios. Results: A total of 110 children were randomized, 50 % to Fentanyl and 50% to placebo. The mean age was 4.6 years for intervention and 4.1years for control. The leading type of surgery was adeno-tonsillectomy for both groups. The incidence of ED was significantly

lower among children randomized to Fentanyl (14.6%) compared to normal saline (47.3%), p<0.001. Fentanyl was associated with 81% reduction in the odds of emergence delirium (OR=0.19; 95% CI: 0.08- 0.48, p<0.001) in univariate analysis and in multivariate analysis after adjusting for the imbalances in the covariates (OR=0.18; 95% CI: 0.07-0.48; p<0.001). There were no statistical difference in the average time to full recovery between the patients randomized to receive fentanyl and those randomized to control (25.2 vs. 22.6; p=0.189) and majority of the patients in both arms; 96.4% in control and 94.6% in fentanyl group did not experience any immediate complications. Conclusion: In resource constrained settings where halothane and isoflurane anaesthetics are most frequently used , Fentanyl given approximately ten minutes before the end of surgery significantly reduced the risk of ED among children (1-12 years) undergoing adeno-tonsillectomy without affecting the average time to full recovery and immediate complications. Recommendation; Administration of fentanyl 1 mcg/kg towards the end of surgery in children undergoing adeno-tonsillectomy should be considered as a routine practice to prevent