| Project/Area Number |
01570871
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
麻酔学
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| Research Institution | Wakayama Medical Collage |
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Principal Investigator |
SETOYAMA Midori Wakayama Medical Collage Anesthesiology Assistant professor, 医学部, 助手 (20206650)
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| Co-Investigator(Kenkyū-buntansha) |
MIZUMOTO Hiroshi Wakayama Medical Collage Anesthesiology Assistant professor, 医学部, 助手 (00145913)
UENO Osamu Wakayama Rosai Hospital Anestesia Anesthetist-in-chief, 麻酔科, 部長 (10073800)
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| Project Period (FY) |
1989 – 1991
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1991: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1990: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1989: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | Ventilation-perfusion distribution / Functional residual capacity / General anesthesia / Laparotomy / 肺換気血流比分布 / 終末呼気陽圧換気 / 肺シャント率 / 肺ガス交換 / 上腹部手術 / 低血圧麻酔 |
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| Research Abstract |
Mechanism of bypoxiemia during general anesthesia is still controvertial. We measured distributions of ventilation-Perfusion ratio (VA/Q) by six inter gas elimination method or functional residual capasity (FRC) by closed-circuit nitrogen dilution method during operation.
The effect of hypotension induced by prostaglandinEI (PGEl) on pulmonary hemodynamics and gas exchange during general anesthesia was studied. PGE1 reduced systemic and pulmonary arterial blood pressure (SBP and PAP) and increased cardiac output (CO). It was considered to be direct effect to arteriole smooth muscle. Intrapulmonary shunt (shunt) increased significantly while a pattern of VA/Q distribution and dead space (DS) did not change. PGE1 inhibited hypoxic pulmonary vasoconstriction (HPV) by direct effect to constricted vessels and second effect by increased CO.
Halothane-induced hypotension also influenced on pulmonary hemodynamics and gas exchange during general anesthesia. Although SBP and CO reduced, PAP and Pa
… More
O2 did not change significantly. Shunt, width of ventilation distribution and width of perfusion distribution reduced. Inhalation anesthetics all inhibit HPV and worsen blood gases. But in our cases, reduced CO might stimulate HPV response through increased oxygen tension in mixed venous blood.
The effect of hypotension induced by epidural anesthesia during general anesthesia was studied similarly. During hypotension CO, SBP, PAP reduced. Shunt reduced and DS increased. Width of ventilation distribution reduced significantly and a pattern of VA/Q distribution did not change. Decrease in contribute to stimulate HPV response and prevent worsen arterial blood gases.
Measurement of FRC during operation has merely reported. We studied the change of FRC before and after lapalotomy under general anesthesia. FRC increased after lapalotomy while PaO2 unchanged. After lapalotomy trans-diaphragmatic pressure become OmmHg at FRC level. Moreover chest wall pulled toward lateral and upward. The costal angle expanded. These factors made chest wall and diaphragma shift to inspiratory position and FRC increase. Less
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