| Co-Investigator(Kenkyū-buntansha) |
KUDO Tsuyoshi Hirosaki University, School of Medicine, Instructor, 医学部, 助手 (70003407)
MURAOKA Masatoshi Hirosaki University, University Hospital, Instructor, 医学部付属病院, 助手 (90240647)
HASHIMOTO Hiroshi Hirosaki University, University Hospital, Instructor, 医学部付属病院, 助手 (00218421)
ISHIHARA Hironori Hirosaki University, School of Medicine, Associate Professor, 医学部, 助教授 (50111224)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 1997: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1996: ¥2,600,000 (Direct Cost: ¥2,600,000)
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| Research Abstract |
Hypnotic endpoints and/or processed EEG variables, e.g., bispectral index (BIS), 95% spectral edge frequency (95%SEF)and median frequency (MF) have been studied to monitor anaessthetic (hypnosis) depth during total intravenous (i.v.) anaesthesia. In this study, the relationship between the hypnotic endpoints of unresponsiveness to verbal commands (UVC), loss of eyelash reflex (LER) and body movement response to mechanical nasal membrane stimulation (abbreviated as NBMR) vs. BIS,95% SEF and MF during propofol(]SY.+-。[)fentanyl i.v.anaesthesia is presented. Forty-two patients were randomly assigned to receive either propofol infusion, 30 mg kg<@D1-1@>D1h<@D1-1@>D1 (P,n=22) or propofol infusion, 30 mg kg<@D1-1@>D1h<@D1-1@>D1+fentanyl bolus, 2mug kg<@D1-1@>D1 iv. (PE,n=20). BIS,95% SEF and MF and propofol doses were monitored and recorded at UVC,LER and inhibition of NBMR (INBMR). The BIS values were significantly higher in the PF as compared to the P group, i.e., 74.7(]SY.+-。[)10.9,73.1(]SY.+-。[)10.5 and 47.1(]SY.+-。[)9.2 vs.65.8(]SY.+-。[)9.8,59.6(]SY.+-。[)10 and 33.8(]SY.+-。[)5.7 at UVC,LER and INBMR,respectively. Doses of propofol for achieving the hypnotic endpoints were significantly lower in the PF group as comparedto the P group. Plasma propofol concentrations at INBMR were lower in the PF as compared to the P group (9.2(]SY.+-。[)2.0 mug ml<@D1-1@>D1 ys.14.1(]SY.+-。[)4.2mug ml<@D1-1@>D1). Our results suggest that fentanyl pretreatment potentiates the effects of propofol and achieves the hypnotic endpoints at higher BIS values and lower propofoldoses and concentrations (measured at INBMR) and that the BIS is dependent on the anaesthetic regimen for monitoring the depth of anaesthesia.
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