Effect Of Target-Controlled-Infusion Concentration Of Remifentanil On The MACBAR Of Sevoflurane In Children With Laparoscopic Surgery

Object:To investigate the effects of different target plasma remifentanil concentration on the minimum alveolar concentration for blocking adrenergic response?MACBAR?of sevoflurane during laparoscopic herniorrhaphy in children.Methods:75 children with ASA?-?grade,3-7 years old,scheduled for laparoscopic herniorrhaphy,were randomly divided into 3 groups according to remifentanil target-controlled infusion concentration?0 ng/ml group,1 ng/ml group and 2 ng/ml group?,respectively,each group for 25 patients.Anesthesia was inducted by intravenously injection of remifentanil and inhaled sevoflurane.The pneumoperitoneum was onset when the expected target concentration of remifentanil was obtained and a certain end-tidal sevoflurane had been maintained for at least 20 minutes.The MACBAR of sevoflurane was determined by up-and-down and sequential method.while observing the HR and MAP,3ml of radial artery blood was collected 3minutes before and after the onset of pneumoperitoneum for determination the concentration of epinephrine and noradrenaline.Results:In groups R₀,R₁ and R₂,the MACBAR of sevoflurane were?3.29±0.17?%,?2.12±0.10?%,?1.29±0.11?%,respectively,there were significant differences among groups?P<0.05?.Target controlled infusion of remifentanil 1 ng/ml and 2 ng/ml decreased sevoflurane's MACBAR by36%and 61%,respectively.The changes of HR,MAP,epinephrine and noradrenaline among the three groups related to the laparoscopy stimuli showed no significant differences at similar MACBAR.Conclusion:Target-controlled infusion of remifentanil can reduce the MACBAR of sevoflurane during laparoscopic surgery in children and can effectively inhibit adrenergic response at MACBAR.It provides a rational application of sevoflurane with remifentainil in clinic.