Y Ohnishi

National Cerebral and Cardiovascular Center, Ōsaka, Ōsaka, Japan

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Publications (36)38.88 Total impact

  • N Miura, K Yoshitani, Y Ohnishi, M Kuro
    Journal of Neurosurgical Anesthesiology - J NEUROSURG ANESTHESIOL. 01/2006; 18(4):303-304.
  • T Iwasaki, Y Hayashi, Y Ohnishi, M Kuro
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    ABSTRACT: Our previous study showed that the success rate of cannulation of the internal jugular vein (IJV) was significantly decreased in infants weighing less than 4.0 kg. We prospectively evaluated results of central venous catheterization in 101 infants weighing less than 4.0 kg undergoing cardiac surgery. The first attempt was routinely performed on the right IJV. If the first attempt failed, the anesthesiologist was free to choose the cannulation site. We examined the effects of patient weight and the experience of the anesthesiologist on successful central catheterization and efficacy of the external jugular vein (EJV) if the first attempt failed. The first right IJV cannulation was successful in 53 infants (52.5%) and the overall successful catheterization rate was 82.2%. Success rates of cannulation of the right IJV, left IJV, and EJV were 64, 13, and 6%, respectively. Body weight contributed significantly to successful catheterization, but the experience of the anesthesiologist did not. These results suggest that EJV cannulation improves the successful central catheterization in infants weighing less than 4.0 kg if IJV cannulation fails. Body weight of an infant, but not the experience of the anesthesiologist, contributed to successful catheterization in this patient population.
    Pediatric Cardiology 08/2004; 25(5):503-5. · 1.20 Impact Factor
  • Journal of Neurosurgical Anesthesiology - J NEUROSURG ANESTHESIOL. 01/2004; 16(4).
  • M Shinzawa, Y Ohnishi, M Kuro
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    ABSTRACT: We experienced anesthetic management for six cases of the Batista operation and measured cardiac function before and after cardiopulmonary bypass (CPB) with transesophageal echocardiography. In the successful three patients, left ventricle ejection fraction and ejection time were maintained over 25% and 200 msec after CPB, respectively. In the other three resulting in implantation of left ventricular assist device, ejection fraction remained below 20% and ejection time under 200 msec after CPB. Intraoperative transesophageal echocardiography may be useful not only for monitoring of cardiac function but also for the prediction of prognosis.
    Masui. The Japanese journal of anesthesiology 08/2001; 50(7):758-61.
  • F Handa, Y Ohnishi, Y Takauchi, M Kuro
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    ABSTRACT: Ten pregnancies and 7 deliveries in 5 patients of Marfan syndrome were managed at our institution. Three patients were delivered with a cesarean section under general anesthesia, and one was delivered under epidural anesthesia. Three underwent vaginal delivery with epidural anesthesia. Two patients selected induced abortion, and one had a spontaneous abortion. Six of 7 neonates and all 5 mothers survived without any sequela. One had intrauterine fetal death due to dissection of aortic aneurysm. Simultaneous cesarean section and cardiovascular operation under cardiopulmonary bypass were performed in one case. In the parturient without progress of cardiovascular complication during pregnancy, painless labor under epidural anesthesia is our first choice to minimize hemodynamic derangement. Invasive arterial blood pressure and central venous pressure were monitored in all cases of vaginal delivery for tight hemodynamic control. Epidural anesthesia is also preferred in cases of elective cesarean section for obstetric indication. Emergency cesarean sections are performed in the cases of progressive dissection and urgent obstetric indication. General anesthesia was induced with fentanyl and midazolam to minimize cardiovascular response to tracheal intubation. We emphasize that evaluation of cardiovascular status and multidisciplinary approach are the key in the anesthetic management of parturients with Marfan syndrome.
    Masui. The Japanese journal of anesthesiology 05/2001; 50(4):399-404.
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    ABSTRACT: Haemostatic disorder is one of the most common complications following cardiac surgery with cardiopulmonary bypass (CPB). Tranexamic acid reduces blood loss and allogeneic blood transfusion requirement in cardiac surgery. It had been thought that tranexamic acid inhibited fibrinolysis alone following CPB. In the present study, the haemostatic effects of tranexamic acid (20 mg/kg body weight bolus after induction of anaesthesia followed by continuous infusion at 2 mg/kg/h), including fibrinolysis and platelet function, were investigated in 22 patients (tranexamic acid group n = 12; control group n = 10) undergoing primary cardiac valve surgery. Fibrinolysis following CPB was reduced significantly in the tranexamic acid group. Following protamine administration, the reduction of collagen-induced whole blood platelet aggregation was mitigated significantly in the tranexamic acid group compared with the control group (36% reduction in the tranexamic acid group vs 58% in the control group; p = 0.011), although platelet counts did not differ between the two groups. In conclusion, tranexamic acid not only inhibits fibrinolysis directly, but also may preserve platelet function following CPB.
    Perfusion 12/2000; 15(6):507-13. · 0.94 Impact Factor
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    ABSTRACT: We anesthetized a 47-yr-old man with end-stage hypertrophic cardiomyopathy for heart transplantation. This is the first case of heart transplantation from a patient with brain death, since the organ transplantation law had become valid in Japan. Anesthesia was induced and maintained with fentanyl and diazepam. Aseptic technique was used in inserting and securing all catheters. The patient was assisted by left ventricular assist system, and hemodynamic suppression at anesthetic induction was trivial. Since complete AV block was present at the termination of cardiopulmonary bypass (CPB), VVI pacing and infusion of isoproterenol were started. In addition, nitroglycerin was given for pulmonary vasodilation. The cardiovascular support used for weaning from CPB included dobutamine, isoprote-renol, dopamine and milrinone. Following weaning from CPB sinus rhythm appeared spontaneously and function of the transplanted heart was satisfactory. When the patient was transported to ICU reduction in doses of catecholamines was possible, and dopamine and milrinone were infused. The patient was extubated 10 hours after admission to ICU.
    Masui. The Japanese journal of anesthesiology 07/2000; 49(6):620-5.
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    ABSTRACT: We experienced intraoperative anesthetic management of two cases of heart transplantation in Japan. Both patients were in the end stage of cardiac failure due to dilated cardiomyopathy. One patient had had implantation of left ventricular assist system, and another patient had had implantation of automated cardioveter defibrillator. Transesophageal echocardiography was useful for the monitoring of cardiac function during the operation. Anti-arrythmic therapy including heart pacing and protection of right heart failure are important for the circulatory management of heart transplantation. The anesthesiologist is needed not only for the management of respiration and circulation but also for the prevention of infection and control of the time schedule.
    Masui. The Japanese journal of anesthesiology 06/2000; 49(5):523-9.
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    ABSTRACT: We reviewed the anesthetic management of 16 patients with concomitant severe coronary and carotid artery diseases. Eight patients underwent concomitant operations of coronary artery bypass graft and carotid endarterectomy, while the other 8 patients underwent two stage operation. Candidates for concomitant operations had unstable angina or serious coronary disease such as three vessel disease or severe stenosis of LMT. In comparison, most of patients undergoing two stage operation had symptomatic or occlusive carotid disease. In all cases, anesthesia was maintained with fentanyl and midazolam and the perfusion pressure during cardiopulmonary bypass was maintained above 70 mmHg. Some patients received thiopental or propofol for brain protection. The concomitant operations required much more transfusion and longer operation time than two stage operation. In addition, several cases of the concomitant operation needed intra-aortic balloon pumping or high dose of catecholamines. Indications for concomitant operation or two stage operation have to be determined through discussion among anesthesiologist, neurovascular as well as cardiovascular surgeons.
    Masui. The Japanese journal of anesthesiology 09/1999; 48(8):856-61.
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    ABSTRACT: We examined the anesthetic management of six patients with end-stage dilated and hypertrophic cardiomyopathy for implantation of left ventricular assist system. Although anesthesia was induced only with fentanyl or with combination of fentanyl and diazepam, hemodynamic changes after the anesthetic induction were variable and preoperative evaluation of left ventricular ejection fraction did not predict the hemodynamic changes. After the weaning from cardiopulmonary bypass, the right ventricular support by catecholamines, such as dopamine and dobutamine, and phosphodiesterase III inhibitors, such as amrinone, and pulmonary vasodilation by inhalation of nitric oxide were useful to maintain volume loading to the left ventricular assist system.
    Masui. The Japanese journal of anesthesiology 08/1999; 48(7):767-72.
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    ABSTRACT: The objective of this retrospective study was to investigate efficacy of low-dose aprotinin priming therapy on the requirement of allogeneic transfusion and to identify risk factors for allogeneic transfusion in patients undergoing repeated cardiac operations. The present study includes a critical review of 124 consecutive charts of patients undergoing elective repeat cardiac surgery. We examined the effect of low-dose aprotinin priming therapy on blood loss, amounts of mediastinal drainage following intensive care unit (ICU) administration and the number of units of blood products given during the perioperative period. The rate of nonallogeneic transfusion was not affected by low-dose aprotinin priming therapy, although aprotinin reduced the amount of allogeneic transfusion and the amount of mediastinal drainage 12 h following ICU admission. In conclusion, low-dose aprotinin priming therapy is effective in reducing blood loss and the amount of allogeneic transfusion. However, it failed to improve the rate of cardiac reoperations without allogeneic blood transfusion.
    Perfusion 06/1999; 14(3):189-94. · 0.94 Impact Factor
  • G Iribe, Y Ohnishi, Y Hayashi, M Kuro
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    ABSTRACT: Although several vasodilators are used to control vascular resistance during cardiac surgery, their effects on splanchnic circulation during extracorporeal circulation are unknown. We designed the present noninvasive study to evaluate the effect of prostaglandin E1 and nitroglycerin on portal venous flow during extracorporeal circulation using transesophageal echography. We included 26 patients undergoing cardiac surgery with moderate hypothermic extracorporeal circulation in this study. After obtaining hemodynamic stability under extracorporeal circulation, we measured portal venous diameter, mean flow velocity and the velocity time integral using transesophageal echography and calculated portal venous flow. The patients were assigned to two groups where either prostaglandin E1 (N = 13) or nitroglycerin (N = 13) was administered intravenously to maintain perfusion pressure at the level of 70 mmHg. We measured the same parameters 20 and 40 min following administration of the drug. Visualization of the portal vein was obtained by transesophageal echography in anesthetized patients. Calculated portal venous flow significantly increased in the prostaglandin E1 group, while it did not alter in the nitroglycerin group. The present results indicate that transesophageal echography may be a feasible tool to assess portal venous flow, and that prostaglandin E1 may improve the blood distribution to the splanchnic area and the liver during hypothermic extracorporeal circulation.
    Acta Anaesthesiologica Scandinavica 06/1999; 43(5):520-5. · 2.36 Impact Factor
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    ABSTRACT: Adrenomedullin is a potent vasodilatory peptide originally identified in human pheochromocytoma. Plasma adrenomedullin increases during and after cardiopulmonary bypass (CPB). However, the site at which production of adrenomedullin is augmented has not been identified. In the present study, we examined the contribution of the cerebral vasculature to the production of adrenomedullin in patients before, during, and after CPB. Ten patients undergoing coronary artery bypass grafting with mild hypothermic CPB were studied. Cerebral blood flow was measured using the Kety-Schmidt method before, during, and after CPB. Plasma adrenomedullin concentrations from radial artery and internal jugular bulb blood were measured by radioimmunoassay, and cerebral adrenomedullin production was evaluated. Adrenomedullin production in the cerebral vasculature was significantly enhanced after CPB and correlated with aortic cross-clamping time. The cerebral adrenomedullin production may contribute to the increased plasma level of adrenomedullin after CPB. IMPLICATIONS: Plasma adrenomedullin has been reported to increase in humans after cardiac surgery involving cardiopulmonary bypass. In this study, we demonstrated that cerebral adrenomedullin production may contribute to the increased plasma level of adrenomedullin after cardiopulmonary bypass.
    Anesthesia & Analgesia 06/1999; 88(5):1030-5. · 3.30 Impact Factor
  • Journal of Cardiothoracic and Vascular Anesthesia 09/1998; 12(4):497-8. · 1.45 Impact Factor
  • T Mammoto, Y Hayashi, Y Ohnishi, M Kuro
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    ABSTRACT: Venous air embolism (VAE) and paradoxical air embolism (PAE) are serious complications associated with the sitting position for neurosurgery. Although PAE is the result of VAE, the incidence of PAE according to the severity of VAE has not been investigated systematically in humans. Twenty-one patients scheduled for neurosurgery in the sitting position were investigated prospectively. VAE and PAE were continuously monitored by cardiac two-dimensional 4-chamber view using transesophageal echocardiography (TEE) and the severity of VAE and PAE was quantitatively graded from 0 to 3 by the microbubbles score. Haemodynamic parameters and end-tidal CO2 concentration (PETCO2) during VAE and PAE were also recorded. Microbubbles in the right atrium appeared in all patients and the number of patients involved in grades 0, 1, 2 and 3 of VAE was 0, 10, 3 and 8, respectively. PAE occurred in 3 patients and only followed grade 3 of VAE. PAE always appeared from 20 to 30 s after the most severe VAE. A reduction of PETCO2 and an increase of pulmonary artery pressure were noted during all episodes of grades 2 and 3 VAE. In contrast, a significant reduction of systemic blood pressure occurred in 1 case of grade 2 and 3 cases of grade 3. VAE detected by TEE appeared in all patients undergoing neurosurgery in the sitting position and PAE only occurred following the most severe grade of VAE. To prevent growth of VAE is an important prophylactic for PAE.
    Acta Anaesthesiologica Scandinavica 08/1998; 42(6):643-7. · 2.36 Impact Factor
  • S Inoue, Y Ohnishi, M Kuro
    Journal of Cardiothoracic and Vascular Anesthesia 03/1998; 12(1):67-8. · 1.45 Impact Factor
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    ABSTRACT: Accidental puncture of the vertebral artery during the internal jugular vein cannulation produces lethal sequelae. To prevent this, the cannulation needle must not be inserted too deeply. However, there is no useful guide for the optimal length of insertion of the needle for accessing the internal jugular vein. The authors examined the length of the needle needed to reach the internal jugular vein with three different sizes of needle (16, 20, and 23 gauge). Prospective study. An academic medical center. Patients undergoing cardiovascular surgeries. The cannulation of the internal jugular vein was performed through the right internal jugular vein by the high approach. The needle was slowly advanced, keeping constant negative pressure on the syringe at 45 degrees to the skin surface until blood was aspirated; if blood was not aspirated during insertion, the needle was slowly withdrawn until blood was aspirated. The distance to the internal jugular vein was assessed by calculating the entire length of needle minus the length of needle from the skin surface to the hub. The mean distance to the internal jugular vein ranged from 15.0 to 21.5 mm, and the larger needle required the longer distance to the internal jugular vein. The results may be a useful guide to prevent too deep insertion of the needle during internal jugular vein catheterization, especially when teaching residents who have limited experience with internal jugular vein catheterization.
    Journal of Cardiothoracic and Vascular Anesthesia 05/1997; 11(2):192-4. · 1.45 Impact Factor
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    ABSTRACT: We reviewed 50 recent anesthetic managements of pediatric patients for open heart surgery weighing between 6.5 to 12 kg to evaluate factors contributing to successful management without transfusion. Twenty six cases were managed without transfusion, whereas nine cases required less than 30 ml.kg-1 of transfusion and the other 15 cases needed massive transfusion amounting to more than 50 ml.kg-1. The followings are important factors to complete the open surgery without transfusion; 1) the patient's weight is 9 kg or more, 2) the duration of cardiopulmonary bypass is less than 120 minutes, and 3) intraoperative bleeding is less than 10 ml.kg-1. We could find several advantages in patients without transfusion, compared with those receiving transfusion, such as greater urine output, less bleeding during the surgery, more concentrated platelet and better respiratory condition after the surgery. In addition, the lager the amount of transfusion we observed the more disadvantageous to the patients. Even if transfusion can not be avoided, minimal transfusion of the washed red cell is favorable.
    Masui. The Japanese journal of anesthesiology 03/1997; 46(2):199-204.
  • Journal of Anesthesia 03/1997; 11(1). · 0.87 Impact Factor
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    ABSTRACT: We evaluated clinical efficacy of near infrared spectroscopy (NIR) as a monitoring system for cerebral oxygenation during anesthesia for carotid artery endarterectomy. NIR proved to be affected significantly by clamping of the external carotid artery. The present study suggests that this monitoring system may be useful for evaluation of cerebral blood flow following declamping of the internal carotid artery, although it has some limitations during clamping of the artery.
    Masui. The Japanese journal of anesthesiology 12/1996; 45(11):1420-3.