| Project/Area Number |
04454347
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
Thoracic surgery
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| Research Institution | KYUSHU UNIVERSITY |
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Principal Investigator |
KOHNO Hiroyuki (1993) Assistant Prof. Kyushu Univ. Cardiovasc Surg., 医学部, 講師 (80178227)
富永 隆治 (1992) 九州大学, 医学部, 講師 (70136464)
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| Co-Investigator(Kenkyū-buntansha) |
MASUDA Munetaka Stuff Member Kyushu Univ. Cardiovasc Surg., 医学部, 助手 (10190365)
KAWACHI Yoshito Associate Prof. Kyushu Univ. Cardiovasc Surg., 医学部, 助教授 (80117093)
河野 博之 九州大学, 医学部, 助手 (80178227)
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| Project Period (FY) |
1992 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥6,600,000 (Direct Cost: ¥6,600,000)
Fiscal Year 1993: ¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 1992: ¥4,200,000 (Direct Cost: ¥4,200,000)
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| Keywords | Centrifugal Biventricular bypass / Nonpulsatile Perfusion / Cardiovascular Bypass / Prostaglandin E_1 / Oxygen Consumption / Intra-aortic Balloon Pumping / Renal Sympathetic Nerve Activity / Hypothermia / 無拍動潅流 / 無拍動流 / 体外循環 / 低体温法 / 補助循環 |
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| Research Abstract |
To investigate the responses of the living body under unphysiological state induced by artificial circulation with nonpulsatile blood flow, following studies have been performed.
(1)The effects of pump flow rate and PGE_1 administration on oxygen use during a moderate hypothermic (29ﾟC in rectal temperature) cardiopulmonary bypass (CPB) was investigated in human. The present result suggested that the critical flow rate to maintain adequate tissue oxygenation is somewhere between 1.6 and 1.8 L/min/m^2 during moderate hypothermic CPB and that PGE_1 administration increased the oxygen consumption at a lower flow rate than the critical flow rate, probably by improving tissue level microcirculation.
(2)The effects of intra-aortic balloon pumping (IABP) on renal sympathetic nerve activity (RSNA) was investigated in dogs. The renal sympathetic nerve was monitored directly and IABP was driven. IABP decreased RSNA and renal vascular resistance. Even though the renal arterial pressure decreased by IABP driving, the renal flow increased, suggesting that IABP improved the renal perfusion through the mechanism of the arterial baroreflex.
(3)The effects of hypothermic CPB and profound hypothermic circulatory arrest (PHCA) on RSNA was investigated in rabbits. The body temperature (BT) was decreased by core cooling from 37ﾟC to 18ﾟC and rewarmed to 37ﾟC.RSNA and arterial baroreflex gain decreased as BT decreased, which were restored after rewarming. RSNA disappeared during PHCA but reappeared during normothermic circulatory arrest after rewarming. Thus, hypothermic CPB and PHCA suppresses RSNA.
(4)To establish chronic nonpulsatile blood flow (NPBF) animal model, the centrifugal biventricular bypass was implanted in 9 goats. Six out of 9 animals survived over 2 days, however, no animal survived over 7 days. Goats seemed to be not suitable for chronic NPBF animal model.
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