| Project/Area Number |
12671459
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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 | YAMANASHI MEDICAL UNIVERSITY |
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Principal Investigator |
MATUKAWA Takash YAMANASHI MEDICAL UNIVERSITY, ANESTHESOLOGY, ASSOCIATE PROFESSOR, 医学部, 助教授 (80209519)
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| Co-Investigator(Kenkyū-buntansha) |
KUMAZAWA Teruo YAMANASHI MEDICAL UNIVERSITY, ANESTHESOLOGY, PROFESSOR, 医学部, 教授 (10092404)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,200,000 (Direct Cost: ¥3,200,000)
Fiscal Year 2001: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 2000: ¥2,200,000 (Direct Cost: ¥2,200,000)
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| Keywords | ANESTHESIA / ATROPINE / ELDERLY / WHYPOTHERMIA / MIDAZOLAM / REMEDICATION / TEMPERATURE / THERMOREGULATTON |
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| Research Abstract |
Introduction : Thermoregulatory control is impaired during anesthesia. A lot of drugs impairs the control. Premedication with midazolam produces core hypothermia whereas atropine increases the sweating threshold. We therefore tested the hypothesis that core temperature is well preserved when atropine and midazolam are combined in elderly patients whom we have shown to be at greater risk of hypothermia perioperatively.
Methods : With 1KB approval and informed consent, elderly patients were randomly assigned (n = 10 per group) to premedication with : (1) saline control ; (2) midazolam 0.05 mg kg^<-1> ; (3) atropine 0.01 mg kg^<-1> ; and, (4) midazolam 0.05 mg kg^<-1> combined with atropine 0.01 mg kg^<-1>. Core temperature was recorded from tympanic membrane thermocouples and arterio-venous shunt constriction was evaluated by forearm minus fingertip, skin-temperature gradients. Temperatures were evaluated at the time of premedication and thirty minutes later, just before induction of anaesthesia. Results : Core temperature remained nearly constant in the control patients (0.1 ± 0.2℃), whereas it decreased significantly in the 'patients given midazolam alone (-0.3 ± 0.1℃). Atropine alone increased core temperature (0.3 ± 0.2℃), although the increase was not statistically significant. The combination of midazolam and atropine obliterated the hypothermia induced by midazolam alone (0.0 ± 0.2℃). Initial skin-temperature gradients exceeded 0℃ in all groups, indicating that the patients were vasoconstricted. The gradients were unchanged by premedication with saline or atropine.
Midazolam significantly decreased the gradient (-1.8 ± 1.1℃), as did the combination of midazolam and atropine (-1.4 ± 0.9℃).
Conclusions : We conclude that the thermoregulatory effects of benzodiazepine receptor agonist and cholinergic inhibitors oppose each other and that the combination leaves core temperature unchanged.
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