Effects of fentanyl infusion on tracheal intubation and emergence agitation in preschool children anaesthetized with sevoflurane

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 mu g kg(-1) followed by a continuous infusion of 0.5 mu g kg(-1) h(-1) (F1 group), or a bolus dose of 2 mu g kg(-1) followed by a continuous infusion of 1 mu g 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 mu g kg(-1) followed by a continuous infusion of 1 mu g kg(-1) h(-1) facilitates tracheal intubation and smooth emergence in children anaesthetized using sevoflurane.