Misc - YAMAKAGE Michiaki

Evaluation of a newly developed monitor of deep body temperature

Michiaki Yamakage, Sohshi Iwasaki, Akiyoshi Namiki

Journal of Anesthesia   16 ( 4 ) 354 - 357  2002

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Body temperature management

J Clin Anesth (Jpn)   26   1681 - 1692  2002

Nitrous oxide

Medical Gases and risk management    2002

自験例からみた体温管理

臨床麻酔   26   1681 - 1692  2002

Non-obstetric anesthesia during pregnancy

Practice in Clinical Anesthesia    2002

Respiratory diseases

Anesthesiologists and Consultation    2002

呼吸器系疾患

麻酔科医とコンサルテーション    2002

医療ガス−用途とその作用・管理法−．５．亜酸化窒素

日常診療に役立つ医療ガスと危機管理    2002

妊娠初期・後期患者の非産科手術の麻酔

麻酔科診療プラクティス    2002

たばこにまつわる問題点

臨床麻酔   24   641 - 651  2002

A case report of inflammatory pseudotomors of the liver and spleen

Anesth Resus   38   61 - 63  2002

Anesthetic effects on mitochondrial ATP-sensitive K channel

S Kohro, QH Hogan, Y Nakae, M Yamakage, ZJ Bosnjak

ANESTHESIOLOGY ( LIPPINCOTT WILLIAMS & WILKINS )  95 ( 6 ) 1435 - 1440  2001.12

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Background Volatile anesthetics show an ischemic preconditioning-like cardioprotective effect, whereas intravenous anesthetics, have cardioprotective effects for ischemic-reperfusion injury. Although recent evidence suggests that mitochondrial adenosine triphosphate-regulated potassium (mitoK(ATP)) channels are important in cardiac preconditioning, the effect of anesthetics on mitoK(ATP) is unexplored. Therefore, the authors tested the hypothesis that anesthetics act on the mitoK(ATP), channel and mitochondrial flavoprotein oxidation. Methods: Myocardial cells were isolated from adult guinea pigs. Endogenous mitochondrial flavoprotein fluorescence, an Indicator of mitochondrial flavoprotein oxidation, was monitored with fluorescence microscopy while myocytes were exposed individually for 15 min to isoflurane, sevoflurane, propofol, and pentobarbital. The authors further Investigated the effect of 5-hydroxydeanoate, a specific mitoK(ATP) channel antagonist, on isoflurane- and sevoflurane-induced flavoprotem oxidation. Additionally, the effects of propofol and pentobarbital on isoflurane-induced flavoprotein oxidation were measured. Results: Isoflurane and sevoflurane induced dose-dependent increases in flavoprotein oxidation (Isoflurane: R2 = 0.71, n = 50; sevoflurane: R2 = 0.86, n = 20). The fluorescence increase produced by both isoflurane and sevoflurane was eliminated by 5-hydroxydeanoate. Although propofol and pentobarbital showed no significant effects on flavoprotein oxidation, they both dose-dependently inhibited isoflurane-induced flavoprotein oxidation. Conclusions: Inhalational anesthetics induce flavoprotein oxidation through opening of the mitoK(ATP) channel. This may be an important mechanism contributing to anesthetic-induced preconditioning. Cardioprotective effects of intravenous anesthetics may not be dependent on flavoprotein oxidation, but the administration of propofol or pentobarbital may potentially inhibit the cardioprotective effect of inhalational anesthetics.

Evaluation of Anesthetic Techniques used in Laparoscopic Cholecystectomy

TSUJIGUCHI Naoki, YAMAKAGE Michiaki, KOTAKI Masatoshi, NAMIKI Akiyoshi

日本臨床麻酔学会誌 = The Journal of Japan Society for Clinical Anesthesia   21 ( 9 ) 409 - 415  2001.11

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Mechanisms of direct inhibitory action of propofol on uterine smooth muscle contraction in pregnant rats

N Tsujiguchi, M Yamakage, A Namiki

ANESTHESIOLOGY ( LIPPINCOTT WILLIAMS & WILKINS )  95 ( 5 ) 1245 - 1255  2001.11

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Background: Although propofol directly inhibits uterine smooth muscle contraction, the mechanisms of this effect are still unknown. The current study aimed to clarify the mechanisms of the inhibitory effect of propofol on oxytocin-induced uterine smooth muscle contraction by measuring (1)the concentration of intracellular free Ca2+ ([Ca2+](i)) simultaneously with muscle tension, (2) the amount of intracellular inositol 1,4,5-triphosphate ([IP3](i)), and (3) voltage-dependent Ca2+ channel (VDCC) activity. Methods: Uterine smooth muscle tissues were obtained from pregnant rats (in late gestation). [Ca2+](i) with isometric tension was monitored by the 500-nm light emission ratio of preloaded Ca2+ indicator fura-2. [IP3](i) and VDCC activity were measured by radioimmunoassay and patch clamp techniques, respectively. The uterine smooth muscle was stimulated by 20 nm oxytocin and exposed to propofol (10(-7) similar to 10(-4) M). Results: Propofol had significant inhibitory effects on oxytocin-induced uterine smooth muscle contraction and increased [Ca2+]i in pregnant rats in a dose-dependent manner, without affecting the agonist-receptor binding affinity. Propofol inhibited the increase in [IP3](i) induced by oxytocin. Propofol also inhibited VDCC activity in both activated and inactivated states. The solvent Intralipid((R)) had no effects on these parameters. Conclusions: Propofol inhibits oxytocin-induced uterine smooth muscle contraction, at least in part, by decreasing [Ca2+](i) without affecting agonist-receptor binding; the inhibitory effect of propofol on [Ca2+](i) might be mediated both by a decrease in [IP3](i) and by inhibition of VDCC activity.

Use of the fibreoptic stylet scope (Styletscope (TM)) reduces the hemodynamic response to intubation in normotensive and hypertensive patients

A Kimura, M Yamakage, XD Chen, Y Kamada, A Namiki

CANADIAN JOURNAL OF ANAESTHESIA-JOURNAL CANADIEN D ANESTHESIE ( CANADIAN ANESTHESIOLOGISTS SOC )  48 ( 9 ) 919 - 923  2001.10

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Purpose: To compare hemodynamic changes after tracheal intubation when using a new fibreoptic stylet scope (Styletscope (TM)) and a conventional laryngoscope in normotensive and hypertensive patients. Methods: Normotensive (N; n=30) and hypertensive (H; n=30) patients undergoing general anesthesia participated in this study. Each group was divided into two groups. In one group, patients were intubated by using a stylet scope with a laryngoscope as an adjuvant (S; n= 15 each), while patients in the other group were intubated using a laryngoscope by the usual technique (L; n = 15 each). The time necessary for intubation, hemodynamic changes, and adverse effects were recorded. Results: Patients in the normotensive groups (SN and LN groups) showed significant increases in both systolic and diastolic blood pressures from before induction to one minute after intubation; however, blood pressures in the SN group were significantly lower than those in the LN group. Both systolic and diastolic blood pressures increased after intubation in the LH group, but not in the SH group. Heart rates in all four groups showed significant increases, and there were no differences between heart rates in the stylet scope and laryngoscope groups or between the normotensive and hypertensive groups. The number of patients who complained of sore throat was greater in the laryngoscope groups. Conclusions: Tracheal intubation with a stylet scope can attenuate hemodynamic changes and reduce the incidence of sore throat in comparison with the conventional laryngoscope technique in both normotensive and hypertensive patients.

Production of compound A under low-flow anesthesia is affected by type of anesthetic machine

M Yamakage, A Kimura, XD Chen, N Tsujiguchi, Y Kamada, A Namiki

CANADIAN JOURNAL OF ANAESTHESIA-JOURNAL CANADIEN D ANESTHESIE ( CANADIAN ANESTHESIOLOGISTS SOC )  48 ( 5 ) 435 - 438  2001.05

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Purpose: The purpose was to compare the concentrations of compound A in inspired gas breathed by patients produced by different types of anesthetic machines under prolonged sevoflurane low-flow anesthesia. Methods: The anesthetic machines tested were Excel (TM) 210 SE (Datex-Ohmeda, Louisville, CO), Cicero (TM) (Drager, Lubeck, Germany), and AS/3 (TM) ADU (Datex-Ohmeda, Louisville, CO). Anesthesia expected to last more than four hours was maintained with 2.0% sevoflurane and nitrous oxide (0.5 L(.)min(-1)) / oxygen (0.5 L(.)min(-1)). The concentrations of compound A, obtained from the inspiratory limb of the circle system, were measured using a gas chromatograph. Results: When Excel (TM) and Cicero (TM) were used, concentrations of compound A increased steadily from the baseline values to 28 and 29 (mean) ppm, respectively, at two hours after exposure to sevoflurane and became constant. There was no significant difference between the concentrations of compound A produced by these anesthetic machines. In contrast, the new anesthetic machine AS/3 (TM) was associated with lower concentrations of compound A (6 ppm at one hour. P <0.05 compared with Excel (TM) and Cicero (TM)), and the concentration did not change significantly thereafter. Conclusion: In spite of the use of a conventional carbon dioxide (CO2) absorbent with strong bases. the anesthetic machine AS/3 (TM) with a small volume of canister/soda lime (900 ml/700 ml) produced lower concentrations of compound A than those produced by the other machines.

Different inhibitory effects of volatile anesthetics on T- and L-type voltage-dependent Ca2+ channels in porcine tracheal and bronchial smooth muscles

M Yamakage, XD Chen, N Tsujiguchi, Y Kamada, A Namiki

ANESTHESIOLOGY ( LIPPINCOTT WILLIAMS & WILKINS )  94 ( 4 ) 683 - 693  2001.04

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Background: The distal airway is more important in the regulation of airflow resistance than is the proximal airway, and volatile anesthetics have a greater inhibitory effect on distal airway muscle tone. The authors investigated the different reactivities of airway smooth muscles to volatile anesthetics by measuring porcine tracheal or bronchial (third to fifth generation) smooth muscle tension and intracellular concentration of free Ca2+ ([Ca2+](i)) and by measuring inward Ca2+ currents (I-Ca) through voltage-dependent Ca2+ channels (VDCs). Methods: Intracellular concentration of free Ca2+ was monitored by the 500-nm light emission ratio of Ca2+ indicator fura-2, Isometric tension was measured simultaneously. Whole-cell patch clamp recording techniques were used to investigate the effects of volatile anesthetics on I-Ca in dispersed smooth muscle cells. Isoflurane (0-1.5 minimum alveolar concentration) or sevoflurane (0-1.5 minimum alveolar concentration) was introduced into a bath solution. Results: The volatile anesthetics tested had greater inhibitory effects on carbachol-induced bronchial smooth muscle contraction than on tracheal smooth muscle contraction. These inhibitory effects by the anesthetics on muscle tension were parallel to the inhibitory effects on [Ca2+](i). Although tracheal smooth muscle cells had only L-type VDCs, some bronchial smooth muscle cells (similar to 30%) included T-type VDC, Each of the two anesthetics significantly inhibited the activities of both types of VDCs in a dose-dependent manner; however, the anesthetics had greater inhibitory effects on T-type VDC activity in bronchial smooth muscle. Conclusions: The existence of the T-type VDC in bronchial smooth muscle and the high sensitivity of this channel to volatile anesthetics seem to be, at least in part, responsible for the different reactivities to the anesthetics in tracheal and bronchial smooth muscles.

Celite-activated viscometer Sonoclot can measure the suppressive effect of tranexamic acid on hyperfibrinolysis in cardiac surgery

K. Kamada, M. Yamakage, T. Niiya, N. Tsujiguchi, X. Chen, A. Namiki

Journal of Anesthesia   15 ( 1 ) 17 - 21  2001

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Purpose. To investigate the usefulness of the celite-activated viscometer Sonoclot for monitoring fibrinolytic status in cardiac surgery, we demonstrated the demonstrated effectiveness of high doses of tranexamic acid, an antifibrinolytic agent, in reducing post-operative bleeding. Methods. Thirty-two American Society of Anesthesiologists (ASA) physical status III patients who required cardiac surgery with cardiopulmonary bypass (CPB) were studied. Anesthesia was induced by a high dose of fentanyl and midazolam with oxygen and was maintained by the intermittent administration of these agents. Patients were divided into two groups: the control group (n = 15) and patients receiving tranexamic acid (TA n = 17). The TA group received a high dose (50 mg/kg) of TA twice, once before and once after CPB. The percentage diminishing rate of the Sonoclot tracing 15 min after maximum clot signal (DR15) and the amount of postoperative bleeding were measured. Results. After CPB, DR15 in the control group (mean 28.3%) increased significantly by 45%, and the DR15 in the TA group (16.1%) was significantly lower than that in the control group. The amount of postoperative bleeding in the TA group (546 ml) was significantly less, by 34%, than that in the control group (829 ml). Conclusion. Prophylactic administration of high-dose TA in cardiac surgery reduces postoperative bleeding, and this effect is consistent with changes in the diminishing rate using Sonoclot. The celite-activated viscometer Sonoclot is recommended for use in cardiac surgery for rapid assessment of fibrinolytic status.

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呼吸機能の評価

麻酔のHow To−診断編−    2001

Usefulness of midazolam premedication for volatile induction of anesthesia in adults

J. I. Hattori, M. Yamakage, S. Iwasaki, X. Chen, N. Tsujiguchi, A. Namiki

Journal of Anesthesia   15 ( 2 ) 117 - 119  2001

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