Bispectral monitoring during vital capacity rapid inhalation induction with sevoflurane.
OBJECTIVE
To evaluate the variables of bispectral index (BIS) values during vital capacity rapid inhalation induction (VCRII) with sevoflurane.


METHODS
Randomized, prospective study.


METHODS
University hospital.


METHODS
40 ASA physical status I and II patients scheduled for elective orthopedic surgery with general anesthesia.


METHODS
Patients was divided into two groups, both of which received intravenous (IV) injection of propofol 2 mg/kg followed by inhalation of sevoflurane 3% (Group P), or vital capacity inhalation induction with sevoflurane 8% (Group S). After loss of consciousness, tracheal intubation was performed with vecuronium 0.1 mg/kg.


RESULTS
The induction times in Group P were significantly shorter than those in Group S (p < 0.01). In Group S, BIS values were gradually decreased and maintained the adequate hypnotic levels were maintained during induction. In Group P, although BIS values were rapidly decreased, the values remained higher compared with Group S. The BIS value before intubation in Group S was significantly lower than that in Group P (25 +/- 9 and 38 +/- 7, respectively; p < 0.01). Five of 20 Group P patients had BIS values exceeding 60 before tracheal intubation, but no patient in Group S had a BIS value as high. Mean arterial pressure immediately after intubation in Group S was significantly lower than that in Group P (p < 0.05).


CONCLUSIONS
VCRII with a high concentration of sevoflurane provided adequate BIS values during induction, suggesting that it may allow smoother transition from anesthesia induction to maintenance, and also maintain an adequate hypnotic level in readiness for certain stimuli such as laryngoscopy and tracheal intubation.
Yamaguchi
Shigeki
S
Department of Anesthesiology, Dokkyo University School of Medicine, Mibu, Tochigi, Japan.
Egawa
Hirotoshi
H
Mishio
Mutsuo
M
Okuda
Yasuhisa
Y
Kitajima
Toshimitsu
T
D000328:Adult; D000768:Anesthesia, General; D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D001794:Blood Pressure / Q000187:drug effects; D004569:Electroencephalography / Q000187:drug effects*; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007442:Intubation, Intratracheal; D008297:Male; D008738:Methyl Ethers; D016343:Monitoring, Intraoperative; D019637:Orthopedic Procedures; D015742:Propofol; D011446:Prospective Studies; D000077149:Sevoflurane; D013997:Time Factors; D014797:Vital Capacity
D018685:Anesthetics, Inhalation; D018686:Anesthetics, Intravenous; D008738:Methyl Ethers; D000077149:Sevoflurane; D015742:Propofol