RYRyo Yamamoto

Ryo Yamamoto

*This is an algorithmically generated author record based on publicly available information.

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Ryo Yamamoto has a total of 34 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    Strategies to Maximize the Benefits of Evidence-Based Enteral Nutrition: A Narrative Review

    by Ken-Ichi Kano, Ryo Yamamoto, Minoru Yoshida, Takeaki Sato, Yoshihiro Nishita, Jiro Ito, Kazuki Nagatomo, Hiroyuki Ohbe, Kanako Takahashi, Masayuki Kaku, et al.

    Enteral nutrition (EN) has been reported to have some physiological importance for critically ill patients. However, the advantage of EN over parenteral nutrition remains controversial in recent paradigms. To maximize the benefits and efficiency of EN, implementing measures based on comprehensive evidence is essential. Here, we systematically reviewed EN-related studies and integrated them into the best and most up-to-date EN practices. We extracted studies from 13 systematic reviews during the development of Japanese Critical Care Nutrition Guidelines, summarizing findings on the assessment of enteral feeding intolerance (EFI), the timing of EN, formula composition and nutrients, and method of administration in critically ill adult patients. Multifaceted EFI assessment may be needed in patients for high-risk patients. Early EN may reduce infectious complications, and initiating EN even earlier may offer an additional advantage. High protein intake (≥1.2 g/kg/day) could maintain muscle mass and physical function without increasing gastrointestinal complications. Probiotics, prebiotics, and synbiotics may serve as beneficial options for preventing infection and gastrointestinal complications, although their efficacy depends on the strains, types, and combinations used. For patients with EFI, post-pyloric feeding could be an effective approach, while intermittent feeding may be a safer approach. Both methods should be utilized to achieve nutritional targets. Integrating these nutritional interventions into EN strategies may help maximize their effectiveness and minimize complications. However, careful consideration regarding timing, dosage, nutrient selection, administration methods, and patient selection is required.


  • Open Access

    Effects of Energy Delivery Guided by Indirect Calorimetry in Critically Ill Patients: A Systematic Review and Meta-Analysis

    by Shinichi Watanabe, Hiroo Izumino, Yudai Takatani, Rie Tsutsumi, Takahiro Suzuki, Hiroomi Tatsumi, Ryo Yamamoto, Takeaki Sato, Tomoka Miyagi, Isao Miyajima, et al.

    Background: The utility of using indirect calorimetry (IC) to estimate energy needs and methods for its application to this purpose remain unclear. This systematic review investigated whether using IC to estimate energy expenditure in critically ill patients is more meaningful for improving survival than other estimation methods. Methods: Comprehensive searches were conducted in MEDLINE using PubMed, Cochrane Central Register of Controlled Trials, and Igaku-Chuo-Zasshi up to March 2023. Results: Nine RCTs involving 1178 patients were included in the meta-analysis. The evidence obtained suggested that energy delivery by IC improved short-term mortality (risk ratio, 0.86; 95% confidence interval [CI], 0.70 to 1.06). However, the use of IC did not appear to affect the length of ICU stay (mean difference [MD], 0.86; 95% CI, −0.98 to 2.70) or the duration of mechanical ventilation (MD, 0.66; 95% CI, −0.39 to 1.72). Post hoc analyses using short-term mortality as the outcome found no significant difference by target calories in resting energy expenditure, whereas more frequent IC estimates were associated with lower short-term mortality and were more effective in mechanically ventilated patients. Conclusions: This updated meta-analysis revealed that the use of IC may improve short-term mortality in patients with critical illness and did not increase adverse events.


  • Open Access

    Use of resuscitative endovascular balloon occlusion of the aorta (REBOA) for trauma and its performance in Japan over the past 18 years: A nationwide descriptive study

    by Hiromasa Hoshi, Akira Endo, Ryo Yamamoto, Kazuma Yamakawa, Keisuke Suzuki, Tomohiro Akutsu, Koji Morishita

    Background: Resuscitative endovascular balloon occlusion of the aorta (REBOA) has been used to control massive hemorrhages. Although there is no consensus on the efficacy of REBOA, it remains an option as a bridging therapy in non-trauma centers where trauma surgeons are not available. To better understand the current landscape of REBOA application, we examined changes in its usage, target population, and treatment outcomes in Japan, where immediate hemostasis procedures sometimes cannot be performed. Methods: This retrospective observational study used the Japan Trauma Data Bank data. All cases in which REBOA was performed between January 2004 and December 2021 were included. The primary outcome was the in-hospital mortality rate. We analyzed mortality trends over time according to the number of cases, number of centers, severity of injury, and overall and subgroup mortality associated with REBOA usage. We performed a logistic analysis of mortality trends over time, adjusting for probability of survival based on the trauma and injury severity score. Results: Overall, 2557 patients were treated with REBOA and were deemed eligible for inclusion. The median age of the participants was 55 years, and male patients constituted 65.3% of the study population. Blunt trauma accounted for approximately 93.0% of the cases. The number of cases and facilities that used REBOA increased until 2019. While the injury severity score and revised trauma score did not change throughout the observation period, the hospital mortality rate decreased from 91.3% to 50.9%. The REBOA group without severe head or spine injuries showed greater improvement in mortality than the all-patient group using REBOA and all-trauma patient group. The greatest improvement in mortality was observed in patients with systolic blood pressure ≥80 mmHg. The adjusted odds ratios for hospital mortality steadily declined, even after adjusting for the probability of survival. Conclusions: While there was no significant change in patient severity, mortality of patients treated with REBOA decreased over time. Further research is required to determine the reasons for these improvements in trauma care.