ABSTRACT
Objective To determine the minimum alveolar concentration (MAC) of sevoflurane in Chinese neonates.Methods Thirty ASA Ⅰ or Ⅱ neonates,aged ≤ 28 days,with normal body weight,scheduled for elective surgery under general anesthesia,were enrolled in the study.Anesthesia was induced with inhalation of 6.00％ sevoflurane in oxygen.The infants were tracheal intubated and mechanically ventilated.The inhaled concentration of sevoflurane was adjusted to achieve the preset end-tidal concentration and maintained at this level for 20 min.Skin incision was then performed.The concentration of sevoflurane was determined by modified Dixon's up-and-down method.The initial end-tidal concentration of sevofluren was 3.00％.Each time the concentration increased/decreased by 0.25 ％ in the next infant according to the infant's response.Successful skin incision was defined as no body movement during skin incision.The MAC,ED95 and 95 ％ confidence interval of sevoflurane were calculated using logistic regression analysis.Results The MAC and ED95 (95 ％ confidence interval) of sevoflurane required for successful skin incision were 2.82％ (2.66％-2.98％) and 3.39％ (2.89％-3.89％),respectively,in neonates.Conclusion The MAC of sevoflurane is 2.82 ％ in Chinese neonates and lower than the present reference values previously described in foreign reports.