title: Effect of a bolus dose of fentanyl on the ED₅₀ and ED₉₅ of sevoflurane in neonates.
abstract: BACKGROUND
  The minimum alveolar concentration (MAC) of sevoflurane in neonates is 3.3%, but this value has not been verified in Chinese neonates and the effect of different doses of fentanyl on MAC in neonates has not been investigated. This study was designed to determine the ED₅₀ and ED₉₅ values of sevoflurane in Chinese neonates with and without fentanyl.
  
  
  METHODS
  Ninety-three neonates were randomly assigned to receive sevoflurane alone (control group, n=30), 1 µg/kg sevoflurane (group fent1, n=29), or 2 µg/kg fentanyl (group fent2, n=32). Following inhalational induction and tracheal intubation, the end-tidal concentration of sevoflurane was adjusted to achieve the designated concentration, which was determined using the modified Dixon's up-and-down method starting with 3.0% in each group, with a 0.25% step size. Success was defined as no motor response within 60 s of skin incision.
  
  
  RESULTS
  The MAC (standard deviation) values of sevoflurane were 2.91% (0.27) in the control group, 2.53% (0.31) in the fent1 group, and 2.34% (0.33) in the fent2 group according to Dixon's up-and-down method. Logistic probit regression analysis revealed that the ED₅₀ and ED₉₅ (95% CI) of sevoflurane in neonates were 2.82% (2.66-2.98) and 3.39% (2.89-3.89), respectively, in the control group; 2.44% (2.19-2.68) and 3.30% (2.51-4.09), respectively, in the fent1 group; and 2.21% (1.97-2.45) and 3.11% (2.35-3.88), respectively, in the fent2 group.
  
  
  CONCLUSIONS
  The MAC value of sevoflurane in Chinese neonates was lower than previously reported and was reduced by the addition of fentanyl.
authors.affiliation: Department of Anesthesiology, Guangzhou Women and Children Medical Center, Guangzhou Medical University affiliated Women and Children Medical Center, Guangzhou, China (mainland).
authors.forename: Ying-Jun
authors.initials: YJ
authors.lastname: She
authors.affiliation: Department of Anesthesiology, Guangzhou Women and Children Medical Center, Guangzhou Medical University affiliated Women and Children Medical Center, Guangzhou, China (mainland).
authors.forename: Huai-Zhen
authors.initials: HZ
authors.lastname: Wang
authors.affiliation: Department of Anesthesiology, Guangzhou Women and Children Medical Center, Guangzhou Medical University affiliated Women and Children Medical Center, Guangzhou, China (mainland).
authors.forename: Jun-Xiang
authors.initials: JX
authors.lastname: Huang
authors.affiliation: Department of Anesthesiology, Guangzhou Women and Children Medical Center, Guangzhou Medical University affiliated Women and Children Medical Center, Guangzhou, China (mainland).
authors.forename: Yong-Hong
authors.initials: YH
authors.lastname: Tan
authors.affiliation: Department of Anesthesiology, Guangzhou Women and Children Medical Center, Guangzhou Medical University affiliated Women and Children Medical Center, Guangzhou, China (mainland).
authors.forename: Zi-Xing
authors.initials: ZX
authors.lastname: Wang
authors.affiliation: Department of Anesthesiology, Guangzhou Women and Children Medical Center, Guangzhou Medical University affiliated Women and Children Medical Center, Guangzhou, China (mainland).
authors.forename: Hang
authors.initials: H
authors.lastname: Tian
authors.affiliation: Department of Anesthesiology, Guangzhou Women and Children Medical Center, Guangzhou Medical University affiliated Women and Children Medical Center, Guangzhou, China (mainland).
authors.forename: Xing-Rong
authors.initials: XR
authors.lastname: Song
mesh_terms: D003710:Demography; D004305:Dose-Response Relationship, Drug; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage* / Q000494:pharmacology*; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D008738:Methyl Ethers / Q000008:administration & dosage* / Q000494:pharmacology*; D000077149:Sevoflurane
chemical_list: D008738:Methyl Ethers; D000077149:Sevoflurane; D005283:Fentanyl