| Project/Area Number |
18591698
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Anesthesiology/Resuscitation studies
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| Research Institution | Hamamatsu University School of Medicine |
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Principal Investigator |
KURITA Tadayoshi Hamamatsu University School of Medicine, Department of Anesthesiology and Intensive Care, Assistant Professor (80303569)
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| Project Period (FY) |
2006 – 2007
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| Project Status |
Completed (Fiscal Year 2007)
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| Budget Amount *help |
¥4,100,000 (Direct Cost: ¥3,500,000、Indirect Cost: ¥600,000)
Fiscal Year 2007: ¥2,600,000 (Direct Cost: ¥2,000,000、Indirect Cost: ¥600,000)
Fiscal Year 2006: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Keywords | hemorrhagic shock / inhalational anesthetic / isoflurane / electroencephalogram / pharmacokinetic / pharmacodvnamic |
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| Research Abstract |
Background: We have previously reported that hemorrhage does not alter the electroencephalographic effect of isoflurane under conditions of compensated hemorrhagic shock. Here, we have investigated the influence of decompensated hemorrhagic shock and subsequent fluid resuscitation on the electroencephalographic effect of isoflurane
Methods: Twelve swine were anesthetized through inhalation of 2% isoflurane. The inhalational concentration was then decreased to 0.5% and maintained for 25 min, before being returned to 2% and maintained for 25 min (control period). Hemorrhagic shock was then induced by removing 28 ml kg-Iof blood over 30 min. After a 30-minute stabilization period, the inhalational concentration was varied as in the control period. Finally, fluid infusion was performed over 30 min using a volume of hydroxyethylstarch equivalent to the blood withdrawn. After a 30-minute stabilization period, the inhalational concentration was again varied as in the control period. End-tidal isoflurane concentrations and spectral edge frequency were recorded throughout the study. The pharmacodynamics were characterized using a sigmoidal inhibitory maximal effect model for spectral edge frequency versus effect-site concentration.
Results: Decompensated hemorrhagic shock slightly but significantly shifted the concentration-effect relationship to the left, demonstrating a 1.12-fold decrease in the effect-site concentration required to achieve 50% of the maximal effect in the spectral edge frequency. Fluid resuscitation reversed the onset of isoflurane, which was delayed by hemorrhage, but did not reverse the increase in end-organ sensitivity.
Conclusions: Although decompensated hemorrhagic shock altered the electroencephalographic effect of isoflurane regardless of fluid resuscitation, the change appeared to be minimal, in contrast to several intravenous anesthetics.
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