山元 良 (ヤマモト リョウ)

Yamamoto, Ryo



医学部 救急医学教室 (信濃町)



経歴 【 表示 / 非表示

  • 2006年04月

    東京都済生会中央病院, 初期研修医

  • 2008年04月

    慶應義塾大学医学部, 救急医学, 後期研修医

  • 2012年04月

    済生会横浜市東部病院, 救急科, 医員

  • 2014年05月

    栃木県済生会宇都宮病院, 救急科, 医員

  • 2015年01月

    University of Texas Health Science Center at San Antonio, Department of Surgery/Division of Trauma and Emergency Surgery, Trauma Surgery Fellow

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学歴 【 表示 / 非表示

  • 2000年04月

    慶應義塾, 医学部

    日本, 大学, 卒業

学位 【 表示 / 非表示

  • 学士(医学), 慶應義塾, 課程, 2006年03月

  • 博士(医学), 慶應義塾, 論文, 2019年05月

    Hydrogen gas distribution in organs after inhalation: Real-time monitoring of tissue hydrogen concentration in rat.

免許・資格 【 表示 / 非表示

  • ECFMG certification, 2011年07月


著書 【 表示 / 非表示

論文 【 表示 / 非表示

  • Hydrogen Gas Inhalation Attenuates Endothelial Glycocalyx Damage and Stabilizes Hemodynamics in a Rat Hemorrhagic Shock Model.

    Tamura T, Sano M, Matsuoka T, Yoshizawa J, Yamamoto R, Katsumata Y, Endo J, Homma K, Kajimura M, Suzuki M, Kobayashi E, Sasaki J

    Shock (Augusta, Ga.) 54 ( 3 ) 377 - 385 2020年09月

    ISSN  1073-2322

  • Oxygen administration in patients recovering from cardiac arrest: A narrative review

    Yamamoto R., Yoshizawa J.

    Journal of Intensive Care (Journal of Intensive Care)  8 ( 1 ) 60 2020年08月


    © 2020 The Author(s). High oxygen tension in blood and/or tissue affects clinical outcomes in several diseases. Thus, the optimal target PaO2 for patients recovering from cardiac arrest (CA) has been extensively examined. Many patients develop hypoxic brain injury after the return of spontaneous circulation (ROSC); this supports the need for oxygen administration in patients after CA. Insufficient oxygen delivery due to decreased blood flow to cerebral tissue during CA results in hypoxic brain injury. By contrast, hyperoxia may increase dissolved oxygen in the blood and, subsequently, generate reactive oxygen species that are harmful to neuronal cells. This secondary brain injury is particularly concerning. Although several clinical studies demonstrated that hyperoxia during post-CA care was associated with poor neurological outcomes, considerable debate is ongoing because of inconsistent results. Potential reasons for the conflicting results include differences in the definition of hyperoxia, the timing of exposure to hyperoxia, and PaO2 values used in analyses. Despite the conflicts, exposure to PaO2 > 300 mmHg through administration of unnecessary oxygen should be avoided because no obvious benefit has been demonstrated. The feasibility of titrating oxygen administration by targeting SpO2 at approximately 94% in patients recovering from CA has been demonstrated in pilot randomized controlled trials (RCTs). Such protocols should be further examined.

  • A novel scale for predicting delayed intubation in patients with inhalation injury

    Matsumura K., Yamamoto R., Kamagata T., Kurihara T., Sekine K., Takuma K., Kase K., Sasaki J.

    Burns (Burns)  46 ( 5 ) 1201 - 1207 2020年

    研究論文(学術雑誌), 共著, 査読有り,  ISSN  03054179


    © 2020 Elsevier Ltd and ISBI Background: Strategies to predict delayed airway obstruction in patients with inhalation injury have not been extensively studied. This study aimed to develop a novel scale, predicting the need for Delayed Intubation after inhalation injury (PDI) score. Methods: We retrospectively identified patients with inhalation injury at four tertiary care centers in Japan between 2012 and 2018. We included patients aged 15 or older and excluded those intubated within 30 min after hospital arrival. Predictors for delayed intubation were identified with univariate analyses and scored on the basis of odds ratios. The PDI score was evaluated with the area under the receiver operating characteristic (AUROC) curve and compared with other scaling systems for burn injuries. Results: Data from 158 patients were analyzed; of these patients, 18 (11.4%) were intubated during the delayed phase. Signs of respiratory distress, facial burn, and pharyngolaryngeal swelling observed on laryngoscopy, were identified as predictors for delayed intubation. The discriminatory power of the PDI (AUROC curve = 0.90; 95% confidence interval, 0.83 to 0.97; p < 0.01) was higher than that of the other scaling systems. Conclusions: We developed a novel scale for predicting delayed intubation in inhalation injury. The score should be further validated with other population.

  • Length of hospital stay and mortality associated with burns from assault: a retrospective study with inverse probability weighting analysis.

    Yamamoto R, Toyosaki M, Kurihara T, Sasaki J

    Burns & trauma 8   tkaa001 2020年

    研究論文(学術雑誌), 共著, 査読有り,  ISSN  2321-3868


    Background: Burns resulting from assaults account for considerable morbidity and mortality among patients with burn injuries around the world. However, it is still unclear whether unfavorable clinical outcomes are associated primarily with the severity of the injuries. To elucidate the direct relationship between burns resulting from assaults and mortality and/or length of hospital stays, we performed this study with the hypothesis that burns from assault would be independently associated with fewer hospital-free days than would burns from other causes, regardless of the severity of burn injuries. Methods: We conducted a retrospective cohort study, using a city-wide burn registry (1996-2017) accounting for 14 burn centers in Tokyo, Japan. Patients who arrived within 24 hours after injury were included, and those with self-inflicted burn injuries were excluded. Patients were divided into two groups according to mechanism of burns (assault vs. accident), and the number of hospital-free days until day 30 after injury (a composite of in-hospital death and hospital length of stay) was compared between the groups. To estimate the probability that an injury would be classified as an assault, we calculated propensity scores, using multivariate logistic regression analyses adjusted for known outcome predictors. We also performed an inverse probability weighting (IPW) analysis to compare adjusted numbers of hospital-free days. Results: Of 7419 patients in the registry with burn injuries during the study period, 5119 patients were included in this study. Of these, 113 (2.2%) were injured as a result of assault; they had significantly fewer hospital-free days than did those with burns caused by accident (18 [27] vs. 24 [20] days; coefficient = [Formula: see text]3.4 [[Formula: see text]5.5 to [Formula: see text]1.3] days; p = 0.001). IPW analyses similarly revealed the independent association between assault burn injury and fewer hospital-free days (adjusted coefficient = [Formula: see text]0.6 [[Formula: see text]1.0 to [Formula: see text]0.1] days; p = 0.009). Conclusions: Burn from assault was independently associated with fewer hospital-free days, regardless of the severity of burn injuries. The pathophysiological mechanism underlying the relationship should be further studied in a prospective observational study.

  • Delays in Surgical Intervention and Temporary Hemostasis Using Resuscitative Endovascular Balloon Occlusion of the aorta (REBOA): Influence of Time to Operating Room on Mortality

    Yamamoto R., Cestero R.F., Muir M.T., Jenkins D.H., Eastridge B.J., Funabiki T., Sasaki J.

    American Journal of Surgery (American Journal of Surgery)  2020年

    ISSN  00029610


    © 2020 Elsevier Inc. Background: The optimal candidates for resuscitative endovascular balloon occlusion of the aorta (REBOA) remain unclear. We hypothesized that patients who experience delays in surgical intervention would benefit from REBOA. Methods: Using the Japan Trauma Databank (2014–2019), patients transferred to the operating room (OR) within 3 h were identified. Patients treated with REBOA were matched with those without REBOA using propensity scores, and further divided based on the transfer time to OR: ≤ 1 h (early), 1–2 h (delayed), and >2 h (significantly-delayed). Survival to discharge was compared. Results: Among 5258 patients, 310 underwent REBOA. In 223 matched pairs, patients treated with REBOA had improved survival (56.5% vs. 31.8%; p < 0.01), although in-hospital mortality was reduced by REBOA only in the delayed and significantly-delayed subgroups (HR = 0.43 [0.28–0.65] and 0.42 [0.25–0.71]). Conclusions: REBOA-treated trauma patients who experience delays in surgical intervention (>1 h) have improved survival.

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総説・解説等 【 表示 / 非表示

研究発表 【 表示 / 非表示

  • 【「CTにて確定診断」それって本当?救急CTの得意・不得意と落とし穴】自転車転倒による腹部鈍的外傷

    山元 良

    Emer Log, 2020年04月, 口頭(一般), (株)メディカ出版

  • 難治性非けいれん性てんかん重積状態を認めたが予後良好であった高齢者の一例

    南 幸治, 山中 隆広, 山元 良, 佐々木 淳一

    日本救急医学会関東地方会雑誌, 2020年01月, 口頭(一般), 日本救急医学会-関東地方会

  • 横浜市における外傷センター選定基準の検討

    矢島 慶太郎, 山元 良, 山崎 元靖, 北野 光秀

    日本救急医学会関東地方会雑誌, 2020年01月, 口頭(一般), 日本救急医学会-関東地方会

  • 経眼窩的穿通性外傷による前頭蓋底開放骨折の一例

    栗原 里沙, 間崎 光, 増澤 佑哉, 拝殿 明奈, 豊崎 光信, 山元 良, 佐藤 幸男, 栗原 智宏, 佐々木 淳一

    日本救急医学会関東地方会雑誌, 2020年01月, 口頭(一般), 日本救急医学会-関東地方会

  • 観戦中の硬式野球ボールによる小児外傷の2例

    鈴木 将平, 拜殿 明奈, 山元 良, 佐藤 幸男, 栗原 智宏, 佐々木 淳一

    日本救急医学会関東地方会雑誌, 2020年01月, 口頭(一般), 日本救急医学会-関東地方会

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競争的資金等の研究課題 【 表示 / 非表示

  • 水素ガスを利用した腸管虚血に対する新規治療法の開発


    文部科学省・日本学術振興会, 科学研究費助成事業, 山元 良, 若手研究, 補助金,  代表

  • 日本外傷データバンクを用いた大動脈遮断カテーテルの救命効果の検討


    日本損害保険協会, 2018年度交通事故医療研究助成, 山元良, 補助金,  代表



  • Retention of Focused Transthoracic Echocardiography Skill


    Betty and Bob Kelso Distinguished Chair in Burn and Trauma Surgery/Military Health Institute , Fellowship Stipend for the Advancement of Trauma and Burn Knowledge, RYO YAMAMOTO, 補助金,  代表


    The purpose of this prospective observational study is to determine if skills of focused transthoracic echocardiography gained by a 2-hour training are decayed in three months.


担当授業科目 【 表示 / 非表示

  • 救急医学講義


  • 救急医学講義


  • 救急医学講義


担当経験のある授業科目 【 表示 / 非表示

  • 救急科

    慶應義塾, 2017年度, 専門科目


所属学協会 【 表示 / 非表示

  • 日本熱傷学会, 

  • 日本消化器外科学会, 

  • Society of Critical Care Medicine, 

  • 日本外傷学会, 

  • 日本救急医学会, 


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委員歴 【 表示 / 非表示

  • 2017年08月

    東京オリンピック・パラリンピック特別委員会委員, 日本外傷学会