title: Epileptogenic effect of sevoflurane: determination of the minimal alveolar concentration of sevoflurane associated with major epileptoid signs in children.
abstract: BACKGROUND
  Sevoflurane has become the gold standard for inhalation induction in children. However in children as in adults, epileptiform electroencephalographic signs have been described under high concentrations of sevoflurane. The aim of this study was to determine the minimal alveolar concentration (MAC) of sevoflurane associated with the occurrence of major epileptiform signs (MES) in 50% children under steady-state conditions. The MAC of MES (MAC MES) was determined in 100% oxygen and with the addition of 50% nitrous oxide or after the injection of alfentanil (ALFENTA).
  
  
  METHODS
  Seventy-nine children (3-11 yr), undergoing elective surgery and premedicated with hydroxyzine were included. After induction by inhalation and tracheal intubation, a 10-min period with a stable expired fraction of sevoflurane was obtained. The MES were defined as rhythmic polyspikes or epileptiform discharges. Electroencephalographic recordings were blindly analyzed by two independent experts. The MAC MES were determined by the Dixon method: the concentration of sevoflurane was determined by the result from the previous patient: increase of 0.2% if MES were absent or decrease of 0.2% if MES were present. Three consecutive series were performed: (1) in 100% oxygen (MAC MESO2); (2) in 50% oxygen and 50% nitrous oxide (MAC MESN2O); and (3) in 100% oxygen with a bolus of alfentanil (MAC MESALFENTA).
  
  
  RESULTS
  The MAC MESO2 was 4.3±0.1% (mean±SD), the MAC MESN2O and the MAC MESALFENTA were higher, respectively: 4.6±0.2% (P=0.01) and 4.6±0.2% (P=0.02).
  
  
  CONCLUSIONS
  In children premedicated with hydroxyzine, the MAC MES of sevoflurane calculated in 100% O2 corresponded to 1.75 surgical MAC. In addition, our results have demonstrated a moderate effect of nitrous oxide and alfentanil in raising the threshold of MES.
authors.affiliation: Department of Anesthesia and Intensive Care, Assistance Publique, Hopitaux de Paris, St. Antoine University Hospital, University Pierre & Marie Curie, Paris, France.
authors.forename: Stephanie
authors.initials: S
authors.lastname: Gibert
authors.forename: Nada
authors.initials: N
authors.lastname: Sabourdin
authors.forename: Nicolas
authors.initials: N
authors.lastname: Louvet
authors.forename: Marie-Laure
authors.initials: ML
authors.lastname: Moutard
authors.forename: Veronique
authors.initials: V
authors.lastname: Piat
authors.forename: Marie-Laurence
authors.initials: ML
authors.lastname: Guye
authors.forename: Agnes
authors.initials: A
authors.lastname: Rigouzzo
authors.forename: Isabelle
authors.initials: I
authors.lastname: Constant
mesh_terms: D018685:Anesthetics, Inhalation / Q000009:adverse effects / Q000378:metabolism*; D002648:Child; D002675:Child, Preschool; D004569:Electroencephalography / Q000187:drug effects* / Q000379:methods; D004827:Epilepsy / Q000139:chemically induced / Q000175:diagnosis / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008738:Methyl Ethers / Q000009:adverse effects / Q000378:metabolism*; D011446:Prospective Studies; D011650:Pulmonary Alveoli / Q000187:drug effects* / Q000378:metabolism*; D000077149:Sevoflurane
chemical_list: D018685:Anesthetics, Inhalation; D008738:Methyl Ethers; D000077149:Sevoflurane