An Effect Of Remifentanil On Minimum Alveolar Concentration Of Isoflurane In Children

BACKGROUND: Remifentanil is a new synthetic opioid, which has been widespreadly used in children due to its unique pharmacokinetic profile. Remifentanil is often combined with isoflurane during paediatric anesthesia. However, there have been fewer reports about the interaction between remifentanil and isoflurane in children in the literature. Therefore, the purpose of this study was to determine the effects of six different remifentanil infusion rates on the minimum alveolar concentration (MAC) of isoflurane in children.METHODS: A total of 108 ASA I-II children aged 4-7 years for a prospective, randomized study were randomly assigned into the six treatment groups, receiving remifentanil at different infusion rates of 0, 0.05, 0.10, 0.15, 0.20, and 0.25 μg/kg/min, respectively, via a motor syringe pump. After induction with propofol (2.0 mg/kg, iv) and succinycholine (1.5 mg/kg, iv), the patients in each group were assigned to a predetermined steady state end-tidal concentration of isoflurane. The isoflurane concentration was adjusted with the up/down technique until at least 12 patients were enrolled in each group. A minimum of 25 min was allowed between the start of the remifentanil infusion and the skin incision . The patients were observed for...