Updated on 2024/11/14

Information

 

写真a

 
NISHIHARA MASAAKI
 
Organization
Kyushu University Hospital Emergency & Critical Care Center Assistant Professor
School of Medicine Department of Medicine(Concurrent)
Title
Assistant Professor
Contact information
メールアドレス
Profile
救命救急センター及び集中治療室において重症患者の初期治療、全身管理に従事している。 重症循環不全患者に対する体外循環に関しての臨床研究にも携わる。 令和5年度からは基礎研究【慢性腎臓病を併存する敗血症における高酸素血症が中枢性交感神経系と予後へ与える影響】にも携わる。
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Degree

  • Oxidative stress in the rostral ventrolateral medulla modulates excitatory and inhibitory inputs in spontaneously hypertensive rats

Research History

  • 2014年4月~2016年3月独立行政法人国立病院機構九州医療センター循環器内科スタッフ

    2014年4月~2016年3月独立行政法人国立病院機構九州医療センター循環器内科スタッフ

Research Interests・Research Keywords

  • Research theme:Impact of hyperoxemia on the central sympathetic nervous system and prognosis in sepsis with comorbid chronic kidney disease.

    Keyword:sepsis, chronic kidney disease, hyperoxia, sympathetic nervous system

    Research period: 2023.4

  • Research theme:Investigation of new onset AF/AFL in critically ill patients in Japan

    Keyword:New onset AF/AFL

    Research period: 2021.4 - 2023.3

  • Research theme:Therapeutic intervention via central sympathetic nerve activity for sepsis complicated by chronic kidney disease

    Keyword:sepsis, chronic kidney disease, sympathetic nerve activity

    Research period: 2020.4 - 2023.3

  • Research theme:Hyperoxemia and neurological outcomes in patients with out-of-hospital cardiac arrest rescued by extracorporeal cardiopulmonary resuscitation: Insight from the nationwide multicenter observational JAAM-OHCA (Japan Association for Acute Medicine) registry

    Keyword:Hyperoxemia, ECPR, neurological outcome

    Research period: 2019.11 - 2023.3

  • Research theme:Predictive factors for long-term neurological outcomes in cardiac arrest patients resuscitated by extracorporeal cardiopulmonary resuscitation

    Keyword:out-of-hospital cardiac arrest, in-hospital cardiac arrest, extracorporeal cardiopulmonary resuscitation, long-term neurological outcome, prognostication

    Research period: 2019.4

  • Research theme:Bleeding events associated factors in adult patients undergoing extracorporeal membrane oxygenation

    Keyword:extracorporeal membrane oxygenation, bleeding events

    Research period: 2017.10 - 2018.3

  • Research theme:The effect of renal denervation on central mechanism of hypertension in hypertensive mice with chronic kidney disease

    Keyword:hypertension, chronic kidney disease, renal denervation, sympathetic nerve activity

    Research period: 2017.3 - 2019.3

Papers

  • Impact of sympathetic hyperactivity induced by brain microglial activation on organ damage in sepsis with chronic kidney disease

    Nishihara, M; Shinohara, K; Ikeda, S; Akahoshi, T; Tsutsui, H

    JOURNAL OF INTENSIVE CARE   12 ( 1 )   31   2024.9   ISSN:2052-0492

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    Language:English   Publisher:Journal of Intensive Care  

    Background: Sympathetic nerve activity (SNA) plays a central role in the pathogenesis of several diseases such as sepsis and chronic kidney disease (CKD). Activation of microglia in the paraventricular nucleus of the hypothalamus (PVN) has been implicated in SNA. The mechanisms responsible for the adverse prognosis observed in sepsis associated with CKD remain to be determined. Therefore, we aimed to clarify the impact of increased SNA resulting from microglial activation on hemodynamics and organ damage in sepsis associated with CKD. Methods and results: In protocol 1, male Sprague–Dawley rats underwent either nephrectomy (Nx) or sham surgery followed by cecal ligation and puncture (CLP) or sham surgery. After CLP, Nx-CLP rats exhibited decreased blood pressure, increased heart rate, elevated serum creatinine and bilirubin levels, and decreased platelet count compared to Nx-Sham rats. Heart rate variability analysis revealed an increased low to high frequency (LF/HF) ratio in Nx-CLP rats, indicating increased SNA. Nx-CLP rats also had higher creatinine and bilirubin levels and lower platelet counts than sham-CLP rats after CLP. In protocol 2, Nx-CLP rats were divided into two subgroups: one received minocycline, an inhibitor of microglial activation, while the other received artificial cerebrospinal fluid (CSF) intracerebroventricularly via an osmotic minipump. The minocycline-treated group (Nx-mino-CLP) showed attenuated hypotensive and increased heart rate responses compared to the CSF-treated group (Nx-CSF-CLP), and the LF/HF ratio was also decreased. Echocardiography showed larger left ventricular dimensions and inferior vena cava in the Nx-mino-CLP group. In addition, creatinine and bilirubin levels were lower and platelet counts were higher in the Nx-mino-CLP group compared to the Nx-CSF-CLP group. Conclusions: In septic rats with concomitant CKD, SNA was significantly enhanced and organ dysfunction was increased. It has been suggested that the mechanism of exacerbated organ dysfunction in these models may involve abnormal systemic hemodynamics, possibly triggered by activation of the central sympathetic nervous system through activation of microglia in the PVN.

    DOI: 10.1186/s40560-024-00742-2

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  • ICU rehabilitation and outcomes in elderly pelvic ring fractures due to high-energy trauma

    Momii Kenta, Yagi Hiroki, Nezu Tomoyuki, Ohsaki Kanji, Man Chen, Tajimi Takahiro, Iyonaga Takeshi, Nishihara Masaaki, Shono Yuji, Maki Jun, Akahoshi Tomohiko, Nakashima Yasuharu

    The Journal of Physical Fitness and Sports Medicine   13 ( 4 )   131 - 137   2024.7   ISSN:21868131 eISSN:21868123

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    Language:English   Publisher:The Japanese Society of Physical Fitness and Sports Medicine  

    <p>Pelvic fractures, accounting for 2–8% of skeletal injuries, present a significant burden in patients with trauma. High-energy incidents often result in severe pelvic trauma accompanied by comorbidities leading to high mortality rates. Managing these complications adds complexity to the treatment process, particularly in older patients who experience longer recovery times and higher injury severity. To improve the long-term quality of life, a multidisciplinary approach is essential. However, rehabilitation feasibility is influenced by the patient’s condition and pelvic fixation stability, necessitating individualized treatment. This study investigated the rehabilitation status and long-term outcomes of older patients with severe polytrauma and pelvic ring fractures caused by high-energy trauma. The results revealed that 79.2% of the patients achieved full weight-bearing, with a median time of 41.5 days, and eventually 58.3% were discharged home. Complications were observed in 83.3% of the patients, with various challenges affecting successful home discharge. Multidisciplinary rehabilitation programs are promising for optimizing outcomes and facilitating recovery in vulnerable patient populations. Still, larger, more focused studies are needed to gain more comprehensive insights into the treatment and recovery of older patients with pelvic ring fractures and severe polytrauma. Understanding these factors is crucial for guiding clinical decision-making and improving long-term outcomes in this population.</p>

    DOI: 10.7600/jpfsm.13.131

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  • Impact of the Coronavirus Disease 2019 (COVID-19) Pandemic on the Severity and the Mortality of Acute Myocardial Infarction in Japan — Analysis From the JROAD-DPC Database —

    Kimura Mitsukuni, Matoba Tetsuya, Nakano Yasuhiro, Katsuki Shunsuke, Sakamoto Kazuo, Nishihara Masaaki, Nagata Takuya, Tahara Yoshio, Nagao Ken, Okura Hiroyuki, Ikeda Takanori, Nakai Michikazu, Tsutsui Hiroyuki

    Circulation Reports   6 ( 6 )   191 - 200   2024.6   eISSN:24340790

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    Language:English   Publisher:The Japanese Circulation Society  

    <p><b><i>Background:</i></b> Coronavirus disease 2019 (COVID-19) has impacted on cardiovascular disease. However, it remains unclear whether the COVID-19 pandemic has impacted on disease severity and patients’ prognosis of acute myocardial infarction (AMI) in Japan.</p><p><b><i>Methods and Results:</i></b> We retrospectively accumulated data from the Japanese Registry of All Cardiac and Vascular Diseases–Diagnosis Procedure Combination (JROAD-DPC) study (April 2019 to March 2021). Patients were divided into a before COVID-19 pandemic group or a during COVID-19 pandemic group. The proportion of patients who presented with cardiogenic shock (Killip class IV) was compared between groups, in association with 30-day mortality as the primary outcome. Killip class IV AMI significantly increased in the during COVID-19 pandemic group (15.7% vs. 14.5% in the before pandemic group, P<0.0001). The 30-day mortality was higher in the during COVID-19 pandemic group (9.6% vs. 9.2% in the before COVID-19 pandemic group, P=0.049). However, there was no significant difference in the adjusted 30-day mortality in each Killip class between the before and during COVID-19 pandemic groups.</p><p><b><i>Conclusions:</i></b> During the early stage of the COVID-19 pandemic in Japan, 30-day mortality of AMI increased, mainly because of the increase of Killip class IV AMI patients. However, irrespective of the COVID-19 pandemic, the adjusted 30-day mortality of each Killip classification group was unchanged.</p>

    DOI: 10.1253/circrep.cr-24-0011

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  • 臨牀指針 マムシ咬傷により急性腎不全・腸管壊死に陥り死亡した1例

    高森 信乃介, 赤星 朋比古, 高橋 慶多, 籾井 健太, 彌永 武史, 西原 正章, 大澤 さやか, 生野 雄二, 牧 盾, 徳田 賢太郎, 山浦 健

    臨牀と研究   101 ( 6 )   735 - 738   2024.6   ISSN:0021-4965

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    Language:Japanese   Publisher:大道学館出版部  

    症例は74歳女性で、蛇咬傷、左上肢の腫脹、疼痛を主訴とした。近医皮膚科を受診し手掌に咬傷2ヶ所を認め、抗生剤を処方された。翌日より腫脹の拡張、疼痛の増悪、筋逸脱酵素と肝逸脱酵素上昇を認め、マムシ咬傷を疑った。本例は受傷から24以上経過し左上肢全体の腫脹に全身症状を伴った(Grade V)。セファランチン・抗マムシ血清・抗生剤投与、急性腎不全に対する持続的血液濾過透析(CHDF)、DIC・敗血症に対する治療を行い、開腹し広範な腸管壊死を認めたが治療困難で、第18病日に死亡した。

  • Impact of the Coronavirus Disease 2019(COVID-19) Pandemic on the Severity and the Mortality of Acute Myocardial Infarction in Japan: Analysis From the JROAD-DPC Database(タイトル和訳中)

    Kimura Mitsukuni, Matoba Tetsuya, Nakano Yasuhiro, Katsuki Shunsuke, Sakamoto Kazuo, Nishihara Masaaki, Nagata Takuya, Tahara Yoshio, Nagao Ken, Okura Hiroyuki, Ikeda Takanori, Nakai Michikazu, Tsutsui Hiroyuki

    Circulation Reports   6 ( 6 )   191 - 200   2024.6

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    Language:English   Publisher:(一社)日本循環器学会  

  • Emphysematous pyelonephritis with ST elevation accompanied by reciprocal changes mimicking acute coronary syndrome

    Hatakeyama, K; Shono, Y; Hashimoto, T; Sakamoto, T; Nishihara, M; Iyonaga, T; Mizuguchi, S; Sakamoto, T; Maki, J; Akahoshi, T

    AMERICAN JOURNAL OF EMERGENCY MEDICINE   70   208e5 - 208e7   2023.8   ISSN:0735-6757 eISSN:1532-8171

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    Language:English   Publisher:American Journal of Emergency Medicine  

    Patients with infectious diseases including sepsis can develop ST segment changes on an electrocardiogram (ECG) in the absence of coronary artery disease. However, ST elevation with “reciprocal ST segment depression (RSTD)”, which is recognized as a specific finding for ST-elevated myocardial infarction, is rare in such patients. Although a small number of cases have reported ST-segment elevation in gastritis, cholecystitis, and sepsis, regardless of coronary artery disease, none presented with reciprocal changes. Here, we describe a rare case of a patient with emphysematous pyelonephritis complicating septic shock who developed ST elevation accompanied by reciprocal changes with no coronary occlusion. Emergency physicians should consider the possibility of acute coronary syndrome mimicking, and choose non-invasive diagnostic procedures when investigating the causes of ECG abnormalities associated with critically ill patients.

    DOI: 10.1016/j.ajem.2023.06.038

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  • Emphysematous pyelonephritis with ST elevation accompanied by reciprocal changes mimicking acute coronary syndrome. Reviewed International journal

    Hatakeyama K, Shono Y, Hashimoto T, Sakamoto T, Nishihara M, Iyonaga T, Mizuguchi S, Sakamoto T, Maki J, Akahoshi T.

    2023.8

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  • Contribution of afferent renal nerve signals to acute and chronic blood pressure regulation in stroke-prone spontaneously hypertensive rats

    Ikeda, S; Shinohara, K; Kashihara, S; Matsumoto, S; Yoshida, D; Nakashima, R; Ono, Y; Nishihara, M; Katsurada, K; Tsutsui, H

    HYPERTENSION RESEARCH   46 ( 1 )   268 - 279   2023.1   ISSN:0916-9636 eISSN:1348-4214

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    Language:English   Publisher:Hypertension Research  

    The activation of sympathetic nervous system plays a critical role in the development of hypertension. The input from afferent renal nerves may affect central sympathetic outflow; however, its contribution to the development of hypertension remains unclear. We investigated the role of afferent renal nerves in acute and chronic blood pressure regulation using normotensive Wistar-Kyoto rats (WKY) and stroke-prone spontaneously hypertensive rats (SHRSP). Acute chemical stimulation of afferent renal nerves elicited larger increases in blood pressure and renal sympathetic nerve activity in young 9-week-old SHRSP compared to WKY. Selective afferent renal denervation (ARDN) and conventional total renal denervation (TRDN) ablating both afferent and efferent nerves in young SHRSP revealed that only TRDN, but not ARDN, chronically attenuated blood pressure elevation. ARDN did not affect plasma renin activity or plasma angiotensin II levels, whereas TRDN decreased both. Neither TRDN nor ARDN affected central sympathetic outflow and systemic sympathetic activity determined by neuronal activity in the parvocellular region of hypothalamic paraventricular nucleus and rostral ventrolateral medulla and by plasma and urinary norepinephrine levels, respectively. Renal injury was not apparent in young SHRSP compared with WKY, suggesting that renal afferent input might not be activated in young SHRSP. In conclusion, the chronic input from afferent renal nerves does not contribute to the development of hypertension in SHRSP despite the increased blood pressure response to the acute stimulation of afferent renal nerves. Efferent renal nerves may be involved in the development of hypertension via activation of the renin-angiotensin system in SHRSP.

    DOI: 10.1038/s41440-022-01091-z

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  • Contribution of afferent renal nerve signals to acute and chronic blood pressure regulation in stroke-prone spontaneously hypertensive rats Reviewed International journal

    Ikeda S, Shinohara K, Kashihara S, Matsumoto S, Yoshida D, Nakashima R, Ono Y, Nishihara M, Katsurada K, Tsutsui H

    Hypertension Research   2023.1

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  • 脳卒中易発症性高血圧自然発症ラットにおける急性および慢性血圧調節に対する腎求心性神経シグナルの寄与(Contribution of afferent renal nerve signals to acute and chronic blood pressure regulation in stroke-prone spontaneously hypertensive rats)

    Ikeda Shota, Shinohara Keisuke, Kashihara Soichiro, Matsumoto Sho, Yoshida Daisuke, Nakashima Ryosuke, Ono Yoshiyasu, Nishihara Masaaki, Katsurada Kenichi, Tsutsui Hiroyuki

    Hypertension Research   46 ( 1 )   268 - 279   2023.1   ISSN:0916-9636

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    交感神経興奮を伴う本態性高血圧のモデルである脳卒中易発症性高血圧自然発症ラット(SHRSP)において、対照のWistar-Kyotoラット(WKY)と比較して、腎求心性神経の急性刺激が血圧上昇や交感神経緊張に与える影響について検討した。腎求心性神経の急性化学刺激により、9週齢の若年SHRSPラットではWKYラットに比べて、血圧や腎交感神経活動の大きな上昇が認められた。若年SHRSPラットにおいて、腎求心性神経を選択的に除神経する方法(ARDN)と求心性・遠心性両神経を除神経する方法(TRDN)を行った。その結果、TRDNのみが慢性的に血圧上昇を抑制した。ARDNは血漿レニン活性や血漿アンジオテンシンII濃度に影響を与えなかったが、TRDNは両者を低下させた。TRDNとARDNは、視床下部室傍核と吻側延髄腹外側野の小細胞性領域のニューロン活動や血漿と尿中のノルエピネフリン濃度によって決定される中枢交感神経流出や全身交感神経活性に影響を与えなかった。腎障害はWKYラットと比較して若年SHRSPラットでは明らかではなかったことから、若年SHRSPラットでは腎求心性入力が活性化していない可能性が示唆された。以上より、SHRSPラットでは、腎求心性神経を急性刺激すると血圧が上昇するにもかかわらず、腎求心性神経からの慢性的な入力は高血圧の発症に寄与していないことが示唆された。

  • Impact of Antithrombin Activity Levels Following Recombinant Antithrombin Gamma Therapy in Patients with Sepsis-Induced Disseminated Intravascular Coagulation Reviewed International journal

    Tomohiko Akahoshi, Noriyuki Kaku, Yuji Shono, Yuzo Yamamoto, Keita Takahashi, Takeshi Iyonaga, Kenta Momii, Masaaki Nishihara, Jun Maki, Kentaro Tokuda, Ken Yamaura

    Clinical and Applied Thrombosis/Hemostasis   2022.11

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  • Prediction of intracranial lesions in patients with consciousness disturbance by ultrasonography in the intensive care unit

    Shono, Y; Mezuki, S; Akahoshi, T; Nishihara, M; Kaku, N; Maki, J; Tokuda, K; Kitazono, T

    JOURNAL OF INTERNATIONAL MEDICAL RESEARCH   50 ( 9 )   3000605221119358   2022.9   ISSN:0300-0605 eISSN:1473-2300

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    Language:English   Publisher:Journal of International Medical Research  

    Objective: This study was performed to evaluate the correlation between parameters measured by bedside ultrasonography and detection of intracranial organic lesions in patients with impaired consciousness in an intensive care unit (ICU) setting. Methods: We retrospectively reviewed the medical records of patients who were admitted to our ICU from April 2017 to July 2019. Patients who underwent computed tomography or magnetic resonance imaging examination and measurement of the flow velocity of the carotid and intracranial arteries and the optic nerve sheath diameter by ultrasonography were selected for analysis. Results: In total, 64 patients were analyzed in this study. Of these, intracranial lesions were detected by computed tomography or magnetic resonance imaging in 17 (27%) patients. The left:right ratio of the end-diastolic velocity of the bilateral common carotid artery (CCA-ED ratio) and the pulsatility index of the middle cerebral artery (MCA-PI) were significantly higher in patients with than in those without intracranial lesions. The cut-off value of the CCA-ED ratio was 1.55 (sensitivity, 66.7%; specificity, 81.6%), and that of the MCA-PI was 1.21 (sensitivity, 57.1%; specificity, 76.7%). Conclusion: Bedside ultrasonography is useful for predicting intracranial lesions requiring therapeutic intervention in ICU patients with impaired consciousness.

    DOI: 10.1177/03000605221119358

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  • Prediction of intracranial lesions in patients with consciousness disturbance by ultrasonography in the intensive care unit Reviewed International journal

    Yuji Shono, Satomi Mezuki, Tomohiko Akahoshi, Masaaki Nishihara, Noriyuki Kaku, Jun Maki, Kentaro Tokuda, Takanari Kitazono

    The Journal of International Medical Research   2022.9

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  • Hyperoxemia is Associated With Poor Neurological Outcomes in Patients With Out-of-Hospital Cardiac Arrest Rescued by Extracorporeal Cardiopulmonary Resuscitation: Insight From the Nationwide Multicenter Observational JAAM-OHCA (Japan Association for Acute Medicine) Registry

    Nishihara, M; Hiasa, K; Enzan, N; Ichimura, K; Iyonaga, T; Shono, Y; Kashiura, M; Moriya, T; Kitazono, T; Tsutsui, H

    JOURNAL OF EMERGENCY MEDICINE   63 ( 2 )   221 - 230   2022.8   ISSN:0736-4679 eISSN:1090-1280

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    Language:English   Publisher:Journal of Emergency Medicine  

    Background: Previous studies have shown an association between hyperoxemia and mortality in patients with out-of-hospital cardiac arrest (OHCA) after cardiopulmonary resuscitation (CPR); however, evidence is lacking in the extracorporeal CPR (ECPR) setting. Objective: The aim of this study was to test the hypothesis that hyperoxemia is associated with poor neurological outcomes in patients treated by ECPR. Methods: The Japanese Association for Acute Medicine OHCA Registry is a multicenter, prospective, observational registry of patients from 2014 to 2017. Adult (18 years or older) patients who had undergone ECPR after OHCA were included. Eligible patients were divided into two groups based on the partial pressure of oxygen in arterial blood (PaO2) levels at 24 h after ECPR: the high-PaO2 group (n = 242) defined as PaO2 ≥ 157 mm Hg (median) and the low-PaO2 group (n = 211) defined as PaO2 60 to < 157 mm Hg. The primary outcome was the favorable neurological outcome, defined as a Cerebral Performance Categories Scale score of 1 to 2 at 30 days after OHCA. Results: Of 34,754 patients with OHCA, 453 patients were included. The neurological outcome was significantly lower in the high-PaO2 group than in the low-PaO2 group (15.9 vs. 33.5%; p < 0.001). After adjusting for potential confounders, high PaO2 was negatively associated with favorable neurological outcomes (adjusted odds ratio [aOR] 0.48; 95% confidence interval [CI] 0.24–0.97; p = 0.040). In a multivariate analysis with multiple imputation, high PaO2 was also negatively associated with favorable neurological outcomes (aOR 0.63; 95% CI 0.49–0.81; p < 0.001). Conclusions: Hyperoxemia was associated with worse neurological outcomes in OHCA patients with ECPR.

    DOI: 10.1016/j.jemermed.2022.05.018

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  • Hyperoxemia is Associated With Poor Neurological Outcomes in Patients With Out-of-Hospital Cardiac Arrest Rescued by Extracorporeal Cardiopulmonary Resuscitation: Insight From the Nationwide Multicenter Observational JAAM-OHCA (Japan Association for Acute Medicine) Registry. Reviewed International journal

    Masaaki Nishihara, Ken-Ichi Hiasa, Nobuyuki Enzan, Kenzo Ichimura, Takeshi Iyonaga, Yuji Shono, Masahiro Kashiura, Takashi Moriya, Takanari Kitazono, Hiroyuki Tsutsui

    The Journal of Emergency Medicine   2022.8

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  • Delayed administration of epinephrine is associated with worse neurological outcomes in patients with out-of-hospital cardiac arrest and initial pulseless electrical activity: insight from the nationwide multicentre observational JAAM-OHCA (Japan Association for Acute Medicine) registry

    Enzan, N; Hiasa, K; Ichimura, K; Nishihara, M; Iyonaga, T; Shono, Y; Tohyama, T; Funakoshi, K; Kitazono, T; Tsutsui, H

    EUROPEAN HEART JOURNAL-ACUTE CARDIOVASCULAR CARE   11 ( 5 )   389 - 396   2022.6   ISSN:2048-8726 eISSN:2048-8734

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    Language:English   Publisher:European Heart Journal: Acute Cardiovascular Care  

    Aims: The delayed administration of epinephrine has been proven to worsen the neurological outcomes of patients with out-of-hospital cardiac arrest (OHCA) and shockable rhythm or asystole. We aimed to investigate whether the delayed administration of epinephrine might also worsen the neurological outcomes of patients with witnessed OHCA and initial pulseless electrical activity (PEA). Methods and results: The JAAM-OHCA Registry is a multicentre registry including OHCA patients between 2014 and 2017. Patients with emergency medical services (EMS)-treated OHCA and initial PEA rhythm were included. The primary exposure was the time from the EMS call to the administration of epinephrine. The secondary exposure was the time to epinephrine dichotomized as early (≤15 min) or delayed (>15 min). The primary outcome was the achievement of a favourable neurological outcome, defined as Cerebral Performance Categories Scale 1-2 at 30 days after OHCA. Out of 34-754 patients with OHCA, 3050 patients were included in the present study. After adjusting for potential confounders, the delayed administration of the epinephrine was associated with a lower likelihood of achieving a favourable neurological outcome [adjusted odds ratio (OR) 0.96; 95% confidence interval (CI) 0.93-0.99; P = 0.016]. The percentage of patients who achieved a favourable neurological outcome in the delayed epinephrine group was lower than that in the early epinephrine group (1.3% vs. 4.7%; adjusted OR 0.33; 95% CI 0.15-0.72; P = 0.005). A restricted cubic spline analysis demonstrated that delayed epinephrine administration could decrease the likelihood of achieving a favourable neurological outcome; this was significant within the first 10 min. Conclusions: The delayed administration of epinephrine was associated with worse neurological outcomes in patients with witnessed OHCA patients with initial PEA.

    DOI: 10.1093/ehjacc/zuac026

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  • Delayed administration of epinephrine is associated with worse neurological outcomes in patients with out-of-hospital cardiac arrest and initial pulseless electrical activity: insight from the nationwide multicentre observational JAAM-OHCA (Japan Association for Acute Medicine) registry Reviewed International journal

    Nobuyuki Enzan, Ken Ichi Hiasa, Kenzo Ichimura, Masaaki Nishihara, Takeshi Iyonaga, Yuji Shono, Takeshi Tohyama, Kouta Funakoshi, Takanari Kitazono, Hiroyuki Tsutsui

    European Heart Journal - Acute Cardiovascular Care   2022.6

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  • Association between short-term neurological outcomes and extreme hyperoxia in patients with out-of-hospital cardiac arrest who underwent extracorporeal cardiopulmonary resuscitation: a retrospective observational study from a multicenter registry

    Kashiura, M; Yasuda, H; Kishihara, Y; Tominaga, K; Nishihara, M; Hiasa, KI; Tsutsui, H; Moriya, T

    BMC CARDIOVASCULAR DISORDERS   22 ( 1 )   163   2022.4   ISSN:1471-2261

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    Language:English   Publisher:BMC Cardiovascular Disorders  

    Background: To investigate the impact of hyperoxia that developed immediately after extracorporeal membrane oxygenation (ECMO)-assisted cardiopulmonary resuscitation (ECPR) on patients’ short-term neurological outcomes after out-of-hospital cardiac arrest (OHCA). Methods: This study retrospectively analyzed data from the Japanese OHCA registry from June 2014 to December 2017. We analyzed adult patients (≥ 18 years) who had undergone ECPR. Eligible patients were divided into the following three groups based on their initial partial pressure of oxygen in arterial blood (PaO2) levels after ECMO pump-on: normoxia group, PaO2 ≤ 200 mm Hg; moderate hyperoxia group, 200 mm Hg < PaO2 ≤ 400 mm Hg; and extreme hyperoxia group, PaO2 > 400 mm Hg. The primary and secondary outcomes were 30-day favorable neurological outcomes. Logistic regression statistical analysis model of 30-day favorable neurological outcomes was performed after adjusting for multiple propensity scores calculated using pre-ECPR covariates and for confounding factors post-ECPR. Results: Of the 34,754 patients with OHCA enrolled in the registry, 847 were included. The median PaO2 level was 300 mm Hg (interquartile range: 148–427 mm Hg). Among the eligible patients, 277, 313, and 257 were categorized as normoxic, moderately hyperoxic, and extremely hyperoxic, respectively. Moderate hyperoxia was not significantly associated with 30-day neurologically favorable outcomes compared with normoxia as a reference (adjusted odds ratio, 0.86; 95% confidence interval: 0.55–1.35; p = 0.51). However, extreme hyperoxia was associated with less 30-day neurologically favorable outcomes when compared with normoxia (adjusted odds ratio, 0.48; 95% confidence interval: 0.29–0.82; p = 0.007). Conclusions: For patients with OHCA who received ECPR, extreme hyperoxia (PaO2 > 400 mm Hg) was associated with 30-day poor neurological outcomes. Avoidance of extreme hyperoxia may improve neurological outcomes in patients with OHCA treated with ECPR.

    DOI: 10.1186/s12872-022-02598-6

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  • Association between short-term neurological outcomes and extreme hyperoxia in patients with out-of-hospital cardiac arrest who underwent extracorporeal cardiopulmonary resuscitation: a retrospective observational study from a multicenter registry Reviewed International journal

    BMC Cardiovascular Disorders   2022.4

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  • Impact of Antithrombin Activity Levels Following Recombinant Antithrombin Gamma Therapy in Patients with Sepsis-Induced Disseminated Intravascular Coagulation

    Akahoshi, T; Kaku, N; Shono, Y; Yamamoto, Y; Takahashi, K; Iyonaga, T; Momii, K; Nishihara, M; Maki, J; Tokuda, K; Yamaura, K

    CLINICAL AND APPLIED THROMBOSIS-HEMOSTASIS   28   2022   ISSN:1076-0296 eISSN:1938-2723

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    Publisher:Clinical and Applied Thrombosis/Hemostasis  

    Recombinant antithrombin gamma (rAT) is reported as an effective drug for patients with disseminated intravascular coagulation (DIC) in Japan. As the appropriate dose and targeted AT activity remain unknown, this study aimed to determine these aspects for sepsis-induced DIC. Thirty-one patients with septic shock and DIC with AT levels <70% were treated with rAT between May 2018 and December 2020. The recovery rates from DIC were 32.2% and 63.3% on day 3 and 5 post administration, respectively. Recovery and survival rates were significantly higher in patients who achieved AT activity ≥70% or 80% on day 3 post administration. Receiver operating characteristic curve analysis revealed that the cutoff values of post-treatment AT activity on day 3 for 28-day survival and 5-day recovery from DIC were 79.5% and 81.5%, respectively. Patients who did not achieve AT activity ≥80% on day 3 presented a lower base level of AT activity and lower dose supplementation. Our results suggest that targeted AT activity should be at least 70%, and ideally 80%, and sufficient doses to maintain this activity are required to achieve better outcomes.

    DOI: 10.1177/10760296221135790

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  • Feasibility and efficacy of an ultra-short side branch-dedicated balloon in coronary bifurcation stenting Reviewed International journal

    Yoshinobu Murasato, Masaaki Nishihara, Takahiro Mori, Kyohei Meno, Kodai Shibao, Katsuhiko Takenaka, Kiyotaka Iwasaki

    EuroIntervention   2021.8

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  • Efficacy of thromboelastography in the management of anticoagulation for veno-venous extracorporeal membrane oxygenation in a coronavirus disease 2019 patient: A case report Reviewed International journal

    Ryosuke Nakashima, Masaaki Nishihara, Takeshi Iyonaga, Sho Iwasaka Yuzo Yamamoto, Yuji Shono, Jun Maki, Kentaro Tokuda, Tomohiko Akahoshi, Taiki Higo, Takanari Kitazono, Hiroyuki Tsutsui

    Medicine   2021.6

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  • Olmesartan combined with renal denervation reduces blood pressure in association with sympatho-inhibitory and aldosterone-reducing effects in hypertensive mice with chronic kidney disease Reviewed

    Masaaki Nishihara, Ko Takesue, Yoshitaka Hirooka

    Clinical and Experimental Hypertension   41 ( 3 )   211 - 219   2019.4

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1080/10641963.2018.1465075

  • Renal denervation enhances GABA-ergic input into the PVN leading to blood pressure lowering in chronic kidney disease Reviewed

    Masaaki Nishihara, Ko Takesue, Yoshitaka Hirooka

    Autonomic Neuroscience: Basic and Clinical   204   88 - 97   2017.5

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    DOI: 10.1016/j.autneu.2016.09.018

  • The mechanism of blood pressure regulation by the central nervous system Reviewed

    Masaaki Nishihara, Yoshitaka Hirooka

    Nippon rinsho. Japanese journal of clinical medicine   73 ( 11 )   1798 - 1800   2015.11

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  • Combining irbesartan and trichlormethiazide enhances blood pressure reduction via inhibition of sympathetic activity without adverse effects on metabolism in hypertensive rats with metabolic syndrome Reviewed

    Masaaki Nishihara, Yoshitaka Hirooka, Kenji Sunagawa

    Clinical and Experimental Hypertension   37 ( 1 )   33 - 38   2015.2

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    DOI: 10.3109/10641963.2014.897719

  • [Effect of sympathetic nervous system on circadian rhythm of blood pressure]. Reviewed

    Masaaki Nishihara, Yoshitaka Hirooka

    Nippon rinsho. Japanese journal of clinical medicine   72 ( 8 )   1374 - 1378   2014

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  • Different role of oxidative stress in paraventricular nucleus and rostral ventrolateral medulla in cardiovascular regulation in awake spontaneously hypertensive rats Reviewed

    Masaaki Nishihara, Yoshitaka Hirooka, Takuya Kishi, Kenji Sunagawa

    Journal of hypertension   30 ( 9 )   1758 - 1765   2012.9

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1097/HJH.0b013e32835613d7

  • Oxidative stress in the rostral ventrolateral medulla modulates excitatory and inhibitory inputs in spontaneously hypertensive rats Reviewed

    Masaaki Nishihara, Yoshitaka Hirooka, Ryuichi Matsukawa, Takuya Kishi, Kenji Sunagawa

    Journal of hypertension   30 ( 1 )   97 - 106   2012.1

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    Language:English   Publishing type:Research paper (scientific journal)  

    DOI: 10.1097/HJH.0b013e32834e1df4

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Research Projects

  • 慢性腎臓病を併存する敗血症における高酸素血症が中枢性交感神経系と予後へ与える影響

    Grant number:23K08478  2023 - 2025

    日本学術振興会  科学研究費助成事業  基盤研究(C)

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    Authorship:Principal investigator  Grant type:Scientific research funding

  • 慢性腎臓病を合併した敗血症に対する中枢性交感神経系を介した治療介入の検討

    Grant number:20K09288  2020 - 2022

    日本学術振興会  科学研究費助成事業  基盤研究(C)

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    Authorship:Principal investigator  Grant type:Scientific research funding

Other educational activity and Special note

  • 2018  Special Affairs 

Outline of Social Contribution and International Cooperation activities

  • 日本循環制御医学会の評議員として活動

Activities contributing to policy formation, academic promotion, etc.

  • 2017.4 - 2019.3   日本循環制御学会

    日本循環制御学会の評議員に着任。年に数回の評議委員会へ出席して、国内の当各分野の発展に寄与すべく活発な討議を行う。

Specialized clinical area

  • Biology / Medicine, Dentistry and Pharmacy / Internal Medicine / Cardiology

Clinician qualification

  • Specialist

    日本集中治療医学会

  • Specialist

    The Japanese Circulation Society(JCS)

Year of medical license acquisition

  • 2005

Notable Clinical Activities

  • 2016年度より救急及び集中治療医療に従事する。 成人心停止例への体外式膜型人工肺を用いた心肺蘇生法に関する研究に携わる。