Tomoya Irie

Yokohama City University, Yokohama, Kanagawa, Japan

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Publications (7)9.79 Total impact

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    ABSTRACT: BACKGROUND:: Near-infrared spectroscopy has been used clinically to continuously and noninvasively monitor cerebral oxygen saturation (ScO2). However, there is no gold standard for measuring absolute values of ScO2. Although time-resolved spectroscopy (TRS) is one of the most reliable algorithms that reliably calculate absolute values of ScO2, there are very few clinical studies available. To evaluate the clinical relevance of ScO2 measurements using TRS, we compared ScO2 with jugular venous oxygen saturation (SjO2) during carotid endarterectomy. We also investigated factors associated with cerebral oxygen desaturation during clamping of the carotid artery. METHODS:: Sixty patients who underwent carotid endarterectomy were enrolled. ScO2 was measured by TRS-20 using TRS at 10 minutes before and after clamping of the carotid artery and 10 minutes after unclamping. SjO2 was measured simultaneously. The relationship between ScO2, SjO2, and estimated ScO2 (0.75×SjO2+0.25×SaO2) were examined by simple regression and the Bland-Altman analysis. Factors related to ScO2<60% were investigated by logistic regression analysis. RESULTS:: There was a significant correlation between ScO2 and SjO2 (r=0.49, P<0.002). Bland-Altman analysis revealed narrow limits of agreement between ScO2 and SjO2 (bias, 9.2%; precision, 12.6%), as well as ScO2 and estimated ScO2 (bias, -1.3%; precision, 9.7%). Impaired cerebral hemodynamics (Powers stage 2 or Kuroda type 3) was significantly associated with ScO2<60%. CONCLUSIONS:: ScO2 measured by TRS and SjO2 showed narrow limits of agreement. Reduced ScO2 was significantly associated with impaired cerebral hemodynamics.
    Journal of neurosurgical anesthesiology 12/2012; · 2.41 Impact Factor
  • Journal of cardiothoracic and vascular anesthesia 01/2012; 26(2):e18-9. · 1.06 Impact Factor
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    ABSTRACT: Paraplegia is a serious complication of descending and thoracoabdominal aortic aneurysms (dTAAs and TAAAs) surgery. Motor evoked potentials (MEPs) enable monitoring the functional integrity of motor pathways during dTAA and TAAA surgery. Although MEPs are sensitive to temperature changes, there are few human data on changes of MEPs during mild and deep hypothermia. Therefore, we investigated changes of MEPs in deep hypothermic circulatory arrest (DHCA) in dTAA and TAAA surgery. Fifteen consecutive patients undergoing dTAA and TAAA surgery using DHCA were enrolled. MEPs were elicited and recorded during each degree Celsius change in nasopharyngeal temperature during both the cooling and rewarming phases. Hand and leg skin temperature were also recorded simultaneously. In the cooling phase MEP amplitude decreased lineally in both the hand and leg. The MEP disappeared at ~16°C in both the hand and leg in 10 of 15 patients, but was still elicited in 5 patients. In the rewarming phase MEP in the hand recovered before the temperature reached 20°C for eight patients and 25°C for the other seven patients. In contrast, MEP in the leg recovered below 20°C for two patients and 30°C for three patients. For the other eight patients MEP waves did not recover during the rewarming phase. In the cooling phase of DHCA, MEP disappeared at ~16°C in some patients but was still elicited in others. MEP recovered below 25°C in the hand. Recovery of MEP in the leg was, however, extremely variable.
    Journal of Anesthesia 12/2011; 26(2):160-7. · 0.87 Impact Factor
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    ABSTRACT: To compare cardiac output (CO) measurements acquired using the Flotrac/Vigileo system (Edwards Lifesciences, Irvine, CA) and CO measured by transesophageal echocardiography using the product of the aortic valve area, the time integral of flow at the same site, and the heart rate during abdominal aortic aneurysm (AAA) surgery. A prospective clinical study. Cardiac surgery operating room of 1 heart center hospital. Twenty patients undergoing elective AAA surgery. CO was determined simultaneously using the Flotrac/Vigileo system (CO(AP)) and transesophageal echocardiography (CO(TEE)) as the reference method at 8 time points during AAA surgery. One hundred sixty simultaneous datasets were obtained. The authors observed a significant correlation between CO(AP) and CO(TEE) values (R = 0.56, p < 0.001). Bland-Altman analysis of CO(AP) and CO(TEE) showed a bias of 0.12 L/min and limits of agreement from -1.66 to 1.90 L/min, with a percentage error of 41%. Just after aortic clamping, CO(AP) significantly increased, but CO(TEE) decreased in comparison with previous measurements. There was a significant association among changes in CO(AP) and pulse pressure, heart rate, and central venous pressure (CVP). However, changes in CO(TEE) were only associated with variations in heart rate. CO(AP) values were not clinically acceptable for use in AAA surgery because of wide variations during aortic clamping and declamping. Changes in pulse pressure, heart rate, and CVP were associated with significant changes in CO(AP), whereas only changes in heart rate showed associated changes in CO(TEE).
    Journal of cardiothoracic and vascular anesthesia 09/2011; 26(2):223-6. · 1.06 Impact Factor
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    ABSTRACT: Off-pump coronary artery bypass surgery (CABG) has not abolished the risk of postoperative stroke and delirium seen for on-pump CABG. Advanced arteriosclerotic changes are common in both on-pump and off-pump CABG. We sought to analyze if advanced arteriosclerotic changes are risk factors of stroke or transient ischemic attack (TIA), and delirium after off-pump CABG. Patients undergoing off-pump CABG between 2001 and 2005 were reviewed using medical records (n=685). Potential risk factors of postoperative stroke and delirium were identified from previous studies. Further, variables retrieved from carotid artery duplex scanning as indices of advanced arteriosclerosis, were examined. The incidences of postoperative stroke/TIA and delirium after off-pump CABG were 2.6% (n=18) and 16.4% (n=112), respectively. Carotid artery stenosis >50% was a significant risk factor of stroke or TIA (P=0.02) as well as delirium (P=0.04) after off-pump CABG. A history of atrial fibrillation (AF) (P=0.037) or diabetes mellitus (P=0.041) was a risk factors of postoperative stroke or TIA. In contrast, age over 75 years (P=0.006), creatinine >1.3 mg/dl (99 μmol/l) (P=0.011), a history of hypertension (P=0.001), past history of AF (P=0.024), and smoking (P=0.048) were significant risk factors of postoperative delirium.
    Interactive Cardiovascular and Thoracic Surgery 12/2010; 12(3):379-83. · 1.11 Impact Factor
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    ABSTRACT: Surgical clipping may cause stenosis of parent arteries or occlusion of perforating arteries in cerebral aneurysm surgery. To prevent postoperative motor deficits, motor-evoked potentials (MEPs) have been used. This enables to detect cerebral ischemia. However, the rate of false negatives (motor deficits with preserved MEP) has been relatively higher than in aortic surgery. We hypothesized that postoperative motor deficits with preserved intraoperative MEP do not always represent false negatives. We reviewed medical records of patients for cerebral aneurysms surgery with transcranial MEP monitoring from September 2003 to March 2009. We reviewed aneurysm location and size, abnormal computed tomography findings, and clinical outcome. Motor status was evaluated immediately after extubation and anytime when the symptom of motor deficits was found. One hundred and eleven patients underwent cerebral aneurysm clipping with transcranial MEP. Ninety-eight patients manifested no intraoperative MEP changes and no postoperative motor deficits. Six patients showed intraoperative MEP changes, resulting in no motor deficits in 4 patients with MEP recovery and hemiparesis in 2 without MEP recovery. Four patients of 6 had aneurysm in anterior choroidal artery (AchA). Other 6 patients showed postoperative motor deficits despite preserved intraoperative MEP. Two of 6 patients showed no motor deficits just after extubation, but developed deficits 5 hours after coming out of anesthesia. Only 1 of the 6 patients had aneurysm in AchA. In AchA aneurysm surgery, intraoperative MEP monitoring seems to be useful. False negative in MEP monitoring may include new-onset hemiparesis despite preserved intraoperative MEP.
    Journal of neurosurgical anesthesiology 07/2010; 22(3):247-51. · 2.41 Impact Factor
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    ABSTRACT: Off-pump coronary artery bypass grafting surgery (OPCAB) frequently results in significant jugular bulb desaturation. Although jugular bulb desaturation during OPCAB may be associated with postoperative cerebral injury, routine jugular bulb oximetry appears to be invasive and expensive. We hypothesized that intraoperative hemodynamic compromise during OPCAB due to cardiac displacement is associated with jugular bulb desaturation which correlates with specific hemodynamic and physiological changes. Hemodynamic and physiological data were measured at the following points: (1) before anastomosis of the coronary artery (baseline); (2) during anastomosis of the left anterior descending artery; (3) during anastomosis of the circumflex branch or posterior descending artery; and (4) after chest closure. Arterial, mixed venous, and jugular venous bulb blood gas analyses were performed serially. Jugular bulb desaturation (<or=50%) frequently occurred during surgical displacement of the heart. Mixed venous oxygen saturation (S(VO2)), partial pressure of carbon dioxide (Pa(CO2)), and central venous pressure (CVP) showed a significant relationship with jugular bulb oxygen saturation (r = 0.45) by multivariate linear regression analysis. Multivariate logistic regression analysis also demonstrated that S(VO2) <or= 70%, Pa(CO2) <or= 40 mmHg, and CVP >or= 8 mmHg were likely predictors of the occurrence of jugular bulb desaturation. Changes in S(VO2) and Pa(CO2) were associated with jugular bulb oxygen saturation, and S(VO2) <or= 70%, Pa(CO2) <or= 40 mmHg, and CVP >or= 8 mmHg had a significant odds ratio for jugular bulb desaturation. We suggest that achieving normal values of S(VO2), Pa(CO2) and CVP may be important to prevent cerebral desaturation during OPCAB.
    Journal of Anesthesia 11/2009; 23(4):477-82. · 0.87 Impact Factor