Study on optimum dose of remifentanil in a combined pediatric anesthesia with sevoflurane during inguinal minor surgery

ABSTRACT

BACKGROUND: Remifentanil can maintain hemodynamic stability in pediatric anesthesia. However, it is also known to frequently have hemodynamic adverse effects including hypotension and bradycardia when large doses are used. Therefore, we aimed to find the optimum dose of remifentanil that can minimize the hemodynamic changes when it is used in combination with sevoflurane in pediatric anesthesia. METHODS: We studied 59 patients who were planned for under general anesthesia, aged between 2 and 8 years. They were randomly divided into two groups. The children in the Group S were anesthetized using sevoflurane 1 MAC and those in the Group R were given a combination of sevoflurane 0.5 MAC and remifentanil 0.1?0.2microg/kg/min. During anesthesia, the N2O was maintained at 50% in all subject children and the anesthesiologist recorded hemodynamic changes before, immediately after and at 5, 10, 15, 20, 25 and 30 minutes after tracheal intubation. The total dose of remifentanil administered during the anesthesia was recorded after the completion of the anesthesia. RESULTS: There was no significant difference of blood pressure observed between the two groups. Significant difference of heart rate was observed in the Group R at 5, 10, 15, 20, 25 and 30 minutes after tracheal intubation as compared with the Group S. The average dosage of remifentanil administered during the surgery in the Group R was 0.121 +/- 0.057microg/kg/min. CONCLUSIONS: In pediatric anesthesia, a combined administration of 0.5 MAC sevoflurane and remifentanil (0.12microg/kg/min) could achieve similar degree of the depth of anesthesia and hemodynamic stability as 1 MAC sevoflurane only.