Literature Reviews
The effect of fentanyl on the emergence characteristics after desflurane or sevoflurane anesthesia in children
Cohen I, Finkel J, Hannallah R, et al. Anesthesia & Analgesia 2002;94:1178-81.
Review: The goal of this study was to compare the effect of a single intraoperative dose of fentanyl on emergence characteristics in children undergoing adenoidectomy, after receiving desflurane or sevoflurane as the maintenance anesthetic. In an earlier study, the same group of researchers demonstrated that an intraoperative dose of fentanyl, 2.5mcg/kg was necessary to reduce the incidence of emergence agitation while preserving rapid recovery from general anesthesia with desflurane. The study incorporated the classic up-down method (i.e., if the previous patient's response was positive, then the next lower dose was given, and if the response was negative, then the next larger dose was administered) to determine the effective fentanyl dose. The current study consisted of 100 children, aged 2 - 7 years, American Society of Anesthesiologists physical status I or II, undergoing adenoidectomy with or without bilateral myringotomy and insertion of tubes.
Premedication was not administered to the study group. An inhalation induction consisting of nitrous oxide and oxygen (70%:30%) and sevoflurane was the technique of choice. Following placement of an intravenous catheter, mivacurium was used to facilitate endotracheal intubation. Fentanyl 2.5mcg/kg IV was administered. On account of the high incidence of vomiting noted in the earlier study, each patient in the current study was given ondansetron 0.1mg/kg IV. Patients were randomly assigned to receive either desflurane 4% - 6% or sevoflurane 1.5% - 2.0% with nitrous oxide 2L/min and oxygen 1L/min, for anesthesia maintenance. There was no control group.
At the completion of surgery, sevoflurane or desflurane and nitrous oxide were discontinued simultaneously. An observer blinded to the maintenance inhalation agent used, assessed several critieria: time to first cough, facial grimacing, purposeful movement, eyes opening, and extubation. In addition, discharge times from the PACU to the short-stay recovery unit (SSRU) and from the SSRU to home were recorded.
Following final analysis of the data, this study suggest that there is no significant difference ( P greater than 0.05) between the Desflurane and Sevoflurane groups when comparing the incidence of emergence agitation. The study points out that 20% of their patients were observed to have emergence agitation. An additional finding in this study, demonstrates that emergence was approximately three to five minutes faster with the Desflurane group as compared to the Sevoflurane group. On the contrary, there was no difference between the two groups in terms of the overall time of discharge to home.
Comments: This study is the first to demonstrate that the effective dose of fentanyl (determined by the same group of researchers in an earlier study) 2.5mcg/kg, similarly decreased the incidence of emergence agitation in children undergoing an adenoidectomy with either desflurane or sevoflurane as the maintenance anesthetic. Other studies have examined the concurrent use of midazolam or propofol, but were found not to effectively reduce emergence agitation. The results of this study as with their previous study are worth consideration. Further studies still have to be done regarding the cause or causes of emergence agitation.
Reviewed by Cheryl K. Gooden, MS #include ./footer_include.iphtml