title: Comparison of emergence agitation between sevoflurane/nitrous oxide administration and sevoflurane administration alone in children undergoing adenotonsillectomy with preemptive ketorolac.
abstract: BACKGROUND
  Sevoflurane anesthesia commonly causes emergence agitation (EA) in children. One previous study has reported that the use of nitrous oxide (N2O) during the washout of sevoflurane may reduce EA by decreasing the residual sevoflurane concentration, while many animal studies suggest that N2O poses a potential risk to children. The present study was designed to compare EA in children assigned to receive sevoflurane with N2O (group N) or sevoflurane alone (group S).
  
  
  METHODS
  We enrolled 80 children aged 3-10 years. Anesthesia was induced with 5 mg/kg thiopental sodium, 0.6 mg/kg rocuronium and 0.5 mg/kg ketorolac, and was maintained with 50% N2O and sevoflurane in group N or with sevoflurane alone in group S. The sevoflurane concentration was adjusted with a bispectral index (BIS) of 40-60. After completion of the surgery, N2O and sevoflurane were simultaneously discontinued and replaced with oxygen (O2) at 6 L/min. End-tidal sevoflurane concentration (Et Sevo) (%), BIS at the end of surgery, Et Sevo at recovery of self-respiration and emergence profiles were recorded. EA occurrence, pain score and rescue fentanyl consumption were assessed in the postanesthesia care unit.
  
  
  RESULTS
  Et Sevo was significantly lower in group N (1.9%) than in group S (2.3%) at the end of surgery. However, there were no differences in Et Sevo at recovery of self-respiration, emergence times, the incidence of EA, pain score or dose of rescue fentanyl between the groups.
  
  
  CONCLUSIONS
  In children undergoing adenotonsillectomy with preemptive ketorolac, anesthetic maintenance using sevoflurane alone does not affect the incidence of EA or emergence profiles compared to anesthetic maintenance using sevoflurane with N2O.
authors.affiliation: Department of Anesthesiology and Pain Medicine, Korea University Guro Hospital, Korea University College of Medicine, Seoul, Korea.
authors.forename: Ji Hye
authors.initials: JH
authors.lastname: Park
authors.affiliation: Department of Anesthesiology and Pain Medicine, Korea University Guro Hospital, Korea University College of Medicine, Seoul, Korea.
authors.forename: Byung Gun
authors.initials: BG
authors.lastname: Lim
authors.affiliation: Department of Anesthesiology and Pain Medicine, Korea University Guro Hospital, Korea University College of Medicine, Seoul, Korea.
authors.forename: Hee Zoo
authors.initials: HZ
authors.lastname: Kim
authors.affiliation: Department of Anesthesiology and Pain Medicine, Korea University Guro Hospital, Korea University College of Medicine, Seoul, Korea.
authors.forename: Myoung Hoon
authors.initials: MH
authors.lastname: Kong
authors.affiliation: Department of Anesthesiology and Pain Medicine, Korea University Guro Hospital, Korea University College of Medicine, Seoul, Korea.
authors.forename: Sang Ho
authors.initials: SH
authors.lastname: Lim
authors.affiliation: Department of Anesthesiology and Pain Medicine, Korea University Guro Hospital, Korea University College of Medicine, Seoul, Korea.
authors.forename: Nan Suk
authors.initials: NS
authors.lastname: Kim
authors.affiliation: Department of Anesthesiology and Pain Medicine, Korea University Guro Hospital, Korea University College of Medicine, Seoul, Korea.
authors.forename: Il Ok
authors.initials: IO
authors.lastname: Lee
keywords: Emergence agitation; Nitrous oxide; Sevoflurane; Tonsillectomy and adenoidectomy