Sasaki, Junichi



School of Medicine, Department of Emergency and Critical Care Medicine (Shinanomachi)



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Other Affiliation 【 Display / hide

  • Keio Advanced Research Centers(KARC), Keio Advanced Research Centers(KARC)

Career 【 Display / hide

  • 1989.05


  • 1990.05


  • 1991.05


  • 1993.05


  • 1995.05


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Academic Background 【 Display / hide

  • 1989.03

    Keio University, Faculty of Medicine

    University, Graduated

Academic Degrees 【 Display / hide

  • Doctor of Medical Science, Keio University, Dissertation, 2003.07


Licenses and Qualifications 【 Display / hide

  • 社会医学系専門医協会 社会医学系指導医・専門医

  • ICD (Infection Control Doctor)

  • 日本組織移植学会 認定医

  • 日本外科感染症学会 外科周術期感染管理認定医・教育医

  • 日本化学療法学会 抗菌化学療法認定医

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Research Areas 【 Display / hide

  • Life Science / Emergency medicine (Emergency Medicine)

  • Life Science / Anesthesiology (Critical Care Medicine)

  • Life Science / General surgery and pediatric surgery (Trauma)

  • Life Science / Infectious disease medicine (Infection Control)

Research Keywords 【 Display / hide

  • Trauma

  • Surgical stress

  • Infection Control

  • Burn

Research Themes 【 Display / hide

  • Mechanism of bio-reaction under the surgical stress, 



Papers 【 Display / hide

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

    Yamamoto R., Homma K., Suzuki S., Sano M., Sasaki J.

    Scientific Reports (Scientific Reports)  9 ( 1 )  2019.12

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    © 2019, The Author(s). Hydrogen has therapeutic and preventive effects against various diseases. Although animal and clinical studies have reported promising results, hydrogen distribution in organs after administration remains unclear. Herein, the sequential changes in hydrogen concentration in tissues over time were monitored using a highly sensitive glass microsensor and continuous inhalation of 3% hydrogen gas. The hydrogen concentration was measured in the brain, liver, kidney, mesentery fat and thigh muscle of rats. The maximum concentration, time to saturation, and other measurements representing the dynamics of distribution were obtained from the concentration curves, and the results obtained for different organs were compared. The time to saturation was significantly longer (20.2 vs 6.3–9.4 min. P = 0.004 in all cases) and increased more gradually in muscle than in the other organs. The maximum concentration was the highest in liver and the lowest in the kidney (29.0 ± 2.6 vs 18.0 ± 2.2 μmol/L; P = 0.03 in all cases). The concentration varied significantly depending on the organ (P = 0.03). These results provide the fundamentals for elucidating the mechanisms underlying the in vivo favourable effects of hydrogen gas in mammalian systems.

  • Epinephrine during resuscitation of traumatic cardiac arrest and increased mortality: A post hoc analysis of prospective observational study

    Yamamoto R., Suzuki M., Hayashida K., Yoshizawa J., Sakurai A., Kitamura N., Tagami T., Nakada T., Takeda M., Sasaki J.

    Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine (Scandinavian Journal of Trauma, Resuscitation and Emergency Medicine)  27 ( 1 )  2019.08

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    © 2019 The Author(s). Background: The beneficial effect of epinephrine during resuscitation from out-of-hospital cardiac arrest (OHCA) has been inconclusive, and potential harm has been suggested, particularly in trauma victims. Although no significant improvement in neurological outcomes has been found among resuscitated patients using epinephrine, including trauma patients, the use of epinephrine is recommended in the Advanced Trauma Life Support protocol. Given that the use of vasopressors was reported to be associated with increased mortality in patients with massive bleeding, the undesirable effects of epinephrine during the resuscitation of traumatic OHCA should be elucidated. We hypothesised that resuscitation with epinephrine would increase mortality in patients with OHCA following trauma. Methods: This study is a post-hoc analysis of a prospective, multicentre, observational study on patients with OHCA between January 2012 and March 2013. We included adult patients with traumatic OHCA who were aged ≥15 years and excluded those with missing survival data. Patient data were divided into epinephrine or no-epinephrine groups based on the use of epinephrine during resuscitation at the hospital. Propensity scores were developed to estimate the probability of being assigned to the epinephrine group using multivariate logistic regression analyses adjusted for known survival predictors. The primary outcome was survival 7 days after injury, which was compared among the two groups after propensity score matching. Results: Of the 1125 adults with traumatic OHCA during the study period, 1030 patients were included in this study. Among them, 822 (79.8%) were resuscitated using epinephrine, and 1.1% (9/822) in the epinephrine group and 5.3% (11/208) in the no-epinephrine group survived 7 days after injury. The use of epinephrine was significantly associated with decreased 7-day survival (odds ratio = 0.20; 95% CI = 0.08-0.48; P < 0.01), and this result was confirmed by propensity score-matching analysis, in which 178 matched pairs were examined (adjusted odds ratio = 0.11; 95% CI = 0.01-0.85; P = 0.02). Conclusions: The relationship between the use of epinephrine during resuscitation and decreased 7-day survival was found in patients with OHCA following trauma, and the propensity score-matched analyses validated the results. Resuscitation without epinephrine in traumatic OHCA should be further studied in a randomised controlled trial.

  • Impact of cardiopulmonary resuscitation time on the effectiveness of emergency department thoracotomy after blunt trauma

    Yamamoto R., Suzuki M., Nakama R., Kase K., Sekine K., Kurihara T., Sasaki J.

    European Journal of Trauma and Emergency Surgery (European Journal of Trauma and Emergency Surgery)  45 ( 4 ) 697 - 704 2019.08

    ISSN  18639933

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    © 2018, Springer-Verlag GmbH Germany, part of Springer Nature. Purpose: Debate remains about the threshold cardiopulmonary resuscitation (CPR) duration associated with futile emergency department thoracotomy (EDT). To validate the CPR duration associated with favorable outcomes, we investigated the relationship between CPR duration and return of spontaneous circulation (ROSC) after EDT in blunt trauma. Methods: A retrospective observational study was conducted at three tertiary centers over the last 7 years. We included bluntly injured adults who were pulseless and required EDT at presentation, but excluded those with devastating head injuries. After multivariate logistic regression identified the CRP duration as an independent predictor of ROSC, receiver operating characteristic curves were used to determine the threshold CPR duration. Patient data were divided into short- and long-duration CPR groups based on this threshold, and we developed a propensity score to estimate assignment to the short-duration CPR group. The ROSC rates were compared between groups after matching. Results: Forty patients were eligible for this study and ROSC was obtained in 12. The CPR duration was independently associated with the achievement of ROSC [odds ratio 1.18; 95% confidence interval (CI) 1.01–1.37, P = 0.04], and the threshold CPR duration was 17 min. Among the 14 patients with a short CPR duration, 13 matched with the patients with a long CPR duration, and a short CPR duration was significantly associated with higher rates of ROSC (odds ratio 8.80; 95% CI 1.35–57.43, P = 0.02). Conclusions: A CPR duration < 17 min is independently associated with higher ROSC rates in patients suffering blunt trauma.

  • Nighttime and non-business days are not associated with increased risk of in-hospital mortality in patients with severe sepsis in intensive care units in Japan: The JAAM FORECAST study

    Matsumura Y., Nakada T., Abe T., Ogura H., Shiraishi A., Kushimoto S., Saitoh D., Fujishima S., Mayumi T., Shiino Y., Tarui T., Hifumi T., Otomo Y., Okamoto K., Umemura Y., Kotani J., Sakamoto Y., Sasaki J., Shiraishi S., Takuma K., Tsuruta R., Hagiwara A., Yamakawa K., Masuno T., Takeyama N., Yamashita N., Ikeda H., Ueyama M., Fujimi S., Gando S.

    Journal of Critical Care (Journal of Critical Care)  52   97 - 102 2019.08

    ISSN  08839441

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    © 2019 Elsevier Inc. Purpose: Hospital services are reduced during off-hour such as nighttime or weekend. Investigations of the off-hour effect on initial management and outcomes in sepsis are very limited. Thus, we tested the hypothesis that patients who were diagnosed with severe sepsis during the nighttime or on non-business days had altered initial management and clinical outcomes. Materials and methods: Patients with severe sepsis from 59 ICUs between 2016 and 2017 were enrolled. The patients were categorized according to the diagnosis time or day and were then compared. The primary outcome was in-hospital mortality. Results: One thousand one hundred and forty-eight patients were analyzed; 769 daytime patients, vs. 379 nighttime patients, and 791 business day patients vs. 357 non-business day patients. There were no significant differences in in-hospital mortality between either daytime and nighttime (24.4% vs. 21.4%, P =.27; nighttime, adjusted odds ratio [OR]1.17, 95% confidence interval [CI], 0.87–1.59, P =.30)or between business and non-business days (22.9% vs. 24.6%, P =.55; non-business day, adjusted OR 0.85, 95% CI 0.60–1.22, P =.85). Time to antibiotics was significantly shorter in the nighttime (114 vs. 89 min, P =.0055). Conclusions: Nighttime and weekends were not associated with increased in-hospital mortality of severe sepsis.

  • In-hospital mortality associated with the misdiagnosis or unidentified site of infection at admission

    Abe T., Tokuda Y., Shiraishi A., Fujishima S., Mayumi T., Sugiyama T., Deshpande G., Shiino Y., Hifumi T., Otomo Y., Okamoto K., Kotani J., Sakamoto Y., Sasaki J., Shiraishi S., Takuma K., Hagiwara A., Yamakawa K., Takeyama N., Gando S., Muroya T., Koike K., Anan H., Sugita M., Miki Y., Yamashita H., Kittaka H., Maehara J., Nachi S., Morino K., Hoshino A., Yamaguchi H., Harada M., Ishikura H., Kawakami M., Deguchi Y., Yoshihara H., Hanaki Y., Okada K., Kaneko T., Kiyota K., Shimizu Y.

    Critical Care (Critical Care)  23 ( 1 )  2019.06

    ISSN  13648535

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    © 2019 The Author(s). Background: Rapid detection, early resuscitation, and appropriate antibiotic use are crucial for sepsis care. Accurate identification of the site of infection may facilitate a timely provision of appropriate care. We aimed to investigate the relationship between misdiagnosis of the site of infection at initial examination and in-hospital mortality. Methods: This was a secondary-multicenter prospective cohort study involving 37 emergency departments. Consecutive adult patients with infection from December 2017 to February 2018 were included. Misdiagnosis of the site of infection was defined as a discrepancy between the suspected site of infection at initial examination and that at final diagnosis, including those infections remaining unidentified during hospital admission, whereas correct diagnosis was defined as site concordance. In-hospital mortality was compared between those misdiagnosed and those correctly diagnosed. Results: Of 974 patients included in the analysis, 11.6% were misdiagnosed. Patients diagnosed with lung, intra-abdominal, urinary, soft tissue, and CNS infection at the initial examination, 4.2%, 3.8%, 13.6%, 10.9%, and 58.3% respectively, turned out to have an infection at a different site. In-hospital mortality occurred in 15%. In both generalized estimating equation (GEE) and propensity score-matched models, misdiagnosed patients exhibited higher mortality despite adjustment for patient background, site infection, and severity. The adjusted odds ratios (misdiagnosis vs. correct diagnosis) for in-hospital mortality were 2.66 (95% CI, 1.45-4.89) in the GEE model and 3.03 (95% CI, 1.24-7.38) in the propensity score-matched model. The difference in the absolute risk in the GEE model was 0.11 (0.04-0.18). Conclusions: Among patients with infection, misdiagnosed site of infection is associated with a > 10% increase in in-hospital mortality.

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Papers, etc., Registered in KOARA 【 Display / hide

Research Projects of Competitive Funds, etc. 【 Display / hide

  • オミクス解析から心停止症候群の病態を解明し新規治療法を開発する


    MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), Principal investigator

  • 造影剤投与による急性腎障害の機序解明および医薬応用


    MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (C), Principal investigator


Courses Taught 【 Display / hide











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Courses Previously Taught 【 Display / hide

  • 医療系三学部合同教育

    Keio University


  • 看護医療学部 救急医学・救急看護

    Keio University


  • Emergency medicine

    Keio University



Memberships in Academic Societies 【 Display / hide

  • Japanese Association of Acute Medicine


Committee Experiences 【 Display / hide

  • 2008.01

    専門委員, 独立行政法人医薬品医療機器総合開発機構(PMDA)