Effects of different plasma target concentrations of remifentanil on the MAC(BAR) of sevoflurane in children with laparoscopic surgery

BACKGROUND: To investigate the effects of different plasma target concentrations of remifentanil on the minimum alveolar concentration (MAC) for blocking adrenergic response (BAR) of sevoflurane in children with laparoscopic herniorrhaphy. METHODS: Seventy-five children with 3-7 years old scheduled for laparoscopic herniorrhaphy were randomly divided into group R(0), group R(1,) and group R(2) according to different remifentanil plasma target concentration (0, 1, and 2 ngml(-1)), respectively. The MAC(BAR) of sevoflurane was determined by the up-and-down and sequential method in each group. The concentrations of epinephrine and noradrenaline were also determined at corresponding time points. RESULTS: A total of 52 child patients were used among the anticipated 75 patients. In groups R(0), R(1,) and R(2), the MAC(BAR) of sevoflurane was (3.29 ± 0.17) %, (2.12 ± 0.10) % and (1.29 ± 0.11) %, respectively, and a significant difference was found among the three groups (P<0.05). The changes of epinephrine and noradrenaline concentrations in each group before and after insufflation of carbon dioxide pneumoperitoneum showed no significant differences. CONCLUSION: Remifentanil by target-controlled infusion can effectively reduce the MAC(BAR) of sevoflurane during laparoscopic surgery in children. At a similar effect of MAC(BAR), both the changes of epinephrine and noradrenaline concentrations are not affected by the infusion of different remifentanil target concentrations. TRIAL REGISTRATION: The trial was registered at http://www.chictr.org.cn(ChiCTR1800019393, 8, Nov, 2018).