Changes of Electroencephalographic Bicoherence during Isoflurane Anesthesia Combined with Epidural Anesthesia

  • Satoshi Hagihira
    *Director, Department of Anesthesiology, Osaka Prefectural Habikino Hospital. †Lecturer, Surgical Center, Professor Emeritus, Department of General Medicine, Osaka University Hospital, Osaka, Japan. ‡Director, Department of Anesthesiology, Osaka Prefectural General Hospital, Osaka, Japan. § Professor and Chairman, Department of Anesthesiology, Osaka University Graduate School of Medicine, Osaka,
  • Masaki Takashina
    *Director, Department of Anesthesiology, Osaka Prefectural Habikino Hospital. †Lecturer, Surgical Center, Professor Emeritus, Department of General Medicine, Osaka University Hospital, Osaka, Japan. ‡Director, Department of Anesthesiology, Osaka Prefectural General Hospital, Osaka, Japan. § Professor and Chairman, Department of Anesthesiology, Osaka University Graduate School of Medicine, Osaka,
  • Takahiko Mori
    *Director, Department of Anesthesiology, Osaka Prefectural Habikino Hospital. †Lecturer, Surgical Center, Professor Emeritus, Department of General Medicine, Osaka University Hospital, Osaka, Japan. ‡Director, Department of Anesthesiology, Osaka Prefectural General Hospital, Osaka, Japan. § Professor and Chairman, Department of Anesthesiology, Osaka University Graduate School of Medicine, Osaka,
  • Takashi Mashimo
    *Director, Department of Anesthesiology, Osaka Prefectural Habikino Hospital. †Lecturer, Surgical Center, Professor Emeritus, Department of General Medicine, Osaka University Hospital, Osaka, Japan. ‡Director, Department of Anesthesiology, Osaka Prefectural General Hospital, Osaka, Japan. § Professor and Chairman, Department of Anesthesiology, Osaka University Graduate School of Medicine, Osaka,
  • Ikuto Yoshiya
    *Director, Department of Anesthesiology, Osaka Prefectural Habikino Hospital. †Lecturer, Surgical Center, Professor Emeritus, Department of General Medicine, Osaka University Hospital, Osaka, Japan. ‡Director, Department of Anesthesiology, Osaka Prefectural General Hospital, Osaka, Japan. § Professor and Chairman, Department of Anesthesiology, Osaka University Graduate School of Medicine, Osaka,

抄録

<jats:sec> <jats:title>Background</jats:title> <jats:p>The authors previously reported that, during isoflurane anesthesia, electroencephalographic bicoherence values changed in a fairly restricted region of frequency versus frequency space. The aim of the current study was to clarify the relation between electroencephalographic bicoherence and the isoflurane concentration.</jats:p> </jats:sec> <jats:sec> <jats:title>Methods</jats:title> <jats:p>Thirty elective abdominal surgery patients (male and female, aged 34-77 yr, American Society of Anesthesiologists physical status I-II) were enrolled. After electroencephalogram recording with patients in an awake state, anesthesia was induced with 3 mg/kg thiopental and maintained with oxygen and isoflurane. Continuous epidural anesthesia with 80-100 mg/kg 1% lidocaine was also administered. Using software they developed, the authors continuously recorded the FP1-A1 lead of the electroencephalographic signal and expired isoflurane concentration to an IBM-PC compatible computer. After confirming the steady state of each isoflurane (end-tidal concentration at 0.3, 0.5, 0.7, 0.9, 1.1, 1.3, and 1.5%), electroencephalographic bicoherence values were calculated.</jats:p> </jats:sec> <jats:sec> <jats:title>Results</jats:title> <jats:p>In a light anesthetic state, electroencephalographic bicoherence values were low (generally &lt; or = 15.0%). At increased concentrations of isoflurane, two peaks of electroencephalographic bicoherence emerged along the diagonal line (f1=f2). The peak emerged at around 4.0 Hz and grew higher as isoflurane concentration increased until it reached a plateau (43.8 +/- 3.5%, mean +/- SD) at isoflurane 0.9%. The other peak, at about 10.0 Hz, also became significantly higher and reached a plateau (32.6 +/- 9.2%) at isoflurane 0.9%; at isoflurane 1.3%, however, this peak slightly decreased.</jats:p> </jats:sec> <jats:sec> <jats:title>Conclusion</jats:title> <jats:p>Changes in the height of two electroencephalographic bicoherence peaks correlated well with isoflurane concentration.</jats:p> </jats:sec>

収録刊行物

  • Anesthesiology

    Anesthesiology 97 (6), 1409-1415, 2002-12-01

    Ovid Technologies (Wolters Kluwer Health)

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