Background: Sevoflurane can be used as a sole agent for intubation in children, but studies have suggested that it is associated with emergence agitation. Fentanyl infusions can be used both to facilitate intubation and decrease emergence agitation. We investigated the effects of fentanyl on conditions at intubation and on emergence from sevoflurane anaesthesia without confounding nitrous oxide or premedication.

Methods: IRB approval and informed consent were obtained. Subjects comprised 150 ASA physical status I or II (age, 2-6 yr). Anaesthesia was induced with sevoflurane in oxygen and maintained using a predetermined concentration of sevoflurane. Subjects were randomly allocated to receive one of three doses of fentanyl: vehicle only (control group), a bolus dose of 1 microg kg(-1) followed by a continuous infusion of 0.5 microg kg(-1) h(-1) (F1 group), or a bolus dose of 2 microg kg(-1) followed by a continuous infusion of 1 microg kg(-1) h(-1) (F2 group). Sevoflurane minimum alveolar concentration for tracheal intubation (MAC(TI)) and emergence agitation score were assessed.

Results: MAC(TI) values were 2.49%, 1.61%, and 1.16% in control, F1, and F2 groups, respectively (P<0.05). Agitation scores were 11.5, 7.0, and 2.6 in control, F1, and F2 groups, respectively (P<0.05).

Conclusions: Fentanyl infusion consisting of a bolus dose of 2 microg kg(-1) followed by a continuous infusion of 1 microg kg(-1) h(-1) facilitates tracheal intubation and smooth emergence in children anaesthetized using sevoflurane.

Clinical trial registration: this study was started in 2000 and was finished in 2008. We had no registration number. IRB approval was obtained.