Yasuaki Koyama

Dr. Yasuaki Koyama


Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 January 2022 in Resuscitation
Verified
Journal Article
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YKYasuaki Koyama
Yasuaki Koyama
TMTasuku Matsuyama
Tasuku Matsuyama
YIYoshiaki Inoue
Yoshiaki Inoue

1 February 2018 in The American Journal of Emergency Medicine
Verified
Journal Article
Closed access
YKYasuaki Koyama
Yasuaki Koyama
YIYoshiaki Inoue
Yoshiaki Inoue
SHShuhei Hisago
Shuhei Hisago
AMAiki Marushima
Aiki Marushima
KHKeiichi Hagiya
Keiichi Hagiya
TMTaro Mizutani
Taro Mizutani

21 August 2023 in Journal of Clinical Medicine
Verified
Journal Article
Open access
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SSShinya Suganuma
Shinya Suganuma
MIMasafumi Idei
Masafumi Idei
HNHidehiko Nakano
Hidehiko Nakano
YKYasuaki Koyama
Yasuaki Koyama
HHHideki Hashimoto
Hideki Hashimoto
KNKensuke Nakamura
Kensuke Nakamura
Background: Persistent inflammation, immunosuppression, and catabolism syndrome (PIICS) is known as a prolonged immunodeficiency that occurs after severe infection. Few studies have demonstrated a direct relationship between PIICS and physical dysfunction in post-intensive care syndrome (PICS). We herein investigated how each component of PICS was affected by the diagnosis of PIICS during hospitalization and examined the relationship between PIICS and PICS using PICS assessments performed at the Hitachi General Hospital PICS Clinic. Methods: The 273 patients who visited the PICS clinic at one month after discharge from the ICU at Hitachi General Hospital were included in the study. We used the diagnostic criteria for PIICS described in previous studies. At least two of the following blood test values on day 14 of hospitalization had to be met for a diagnosis of PIICS: C-reactive protein (CRP) > 2.0 mg/dL, albumin (Alb) < 3.0 g/dL, and lymphocytes (Lym) < 800/μL. Blood test values closest to day 14 out of 11–17 days of hospitalization were used. The primary outcome was a Barthel Index (BI) < 90, while secondary outcomes were the results of various PICS assessments, including mental and cognitive impairments, performed at the PICS clinic. We supplemented missing data with multiple imputations by chained equations. We performed a nominal logistic regression analysis with age, sex, BMI, SOFA, and the presence of PIICS as variables for BI < 90. Results: Forty-three out of two hundred seventy-three PICS outpatients met the diagnostic criteria for PIICS during hospitalization. In comparisons with non-PIICS patients, significantly higher severity scores for APACHE II and SOFA and a longer hospital stay were observed in PIICS patients, suggesting a higher clinical severity. The primary outcome, BI, was lower in the PIICS group (97.5 (58.5, 100) vs. 100 (95, 100), p = 0.008), as were the secondary outcomes (FSS-ICU: 35 (31, 35) vs. 35 (35, 35), MRC score: 55 (50.25, 58) vs. 58 (53, 60), grip strength: 16.45 (9.2, 25.47) vs. 20.4 (15.3, 27.7)). No significant differences were noted in mental or cognitive function assessments, such as HADS, IES-R, and SMQ. A multivariable analysis supplemented with missing data revealed that PIICS (odds ratio: 1.23 (1.08–1.40 p = 0.001) and age (odds ratio: 1.007 (1.004–1.01), p < 0.001) correlated with BI < 90, independent of clinical severity such as sequential organ failure assessment (SOFA). Similar results were obtained in the sensitivity analysis excluding missing data. Conclusions: The present study revealed a strong relationship between PIICS and post-discharge PICS physical dysfunction in patients requiring intensive care.

6 May 2022 in BMC Emergency Medicine
Verified
Journal Article
Open access
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YKYasuaki Koyama
Yasuaki Koyama
TMTasuku Matsuyama
Tasuku Matsuyama
TKTakako Kaino
Takako Kaino
THTetsuya Hoshino
Tetsuya Hoshino
JNJunzo Nakao
Junzo Nakao
YIYoshiaki Inoue
Yoshiaki Inoue
Background: The 2020 American Heart Association guidelines recommend the use of a feedback device during chest compressions (CCs). However, these devices are only placed visually by medical personnel on the lower half of the sternum and do not provide feedback on the adequacy of the pressure-delivery position. In this study, we investigated whether medical staff could deliver CCs at the adequate compression position using a feedback device and identified where the inadequate position was compressed. Methods: This simulation-based, prospective single-centre study enrolled 44 medical personnel who were assigned to four different groups based on the standing position and the hand in contact with the feedback device as follows: right–left (R–l), right–right (R–r), left–right (L–r), and left–left (L–l), respectively. The sensor position where the maximal average pressure was applied during CCs using the feedback device were ascertained with a flexible capacitive pressure sensor. We determined if this position is the adequate compression position or not. The intergroup differences in the frequency of the adequate compression position, the maximal average pressure, compression rate, depth and recoil were determined. Results: The frequencies of adequate compression positioning were 55, 50, 58, and 60% in the R–l, R–r, L–r, and L–l groups, respectively, with no significant intergroup difference (p = 0.917). Inadequate position occurred in the front, back, hypothenar and thenar sides. The maximal average pressure did not significantly differ among the groups (p = 0.0781). The average compression rate was 100–110 compressions/min in each group, the average depth was 5–6 cm, and the average recoil was 0.1 cm, with no significant intergroup differences (p = 0.0882, 0.9653, and 0.2757, respectively). Conclusions: We found that only approximately half of the medical staff could deliver CCs using the feedback device at an adequate compression position and the inadequate position occurred in all sides. Resuscitation courses should be designed to educate trainees about the proper placement during CCs using a feedback device while also evaluating the correct compression position.

1 April 2019 in Resuscitation
Verified
Journal Article
Closed access
YKYasuaki Koyama
Yasuaki Koyama
TMTasuku Matsuyama
Tasuku Matsuyama
YIYoshiaki Inoue
Yoshiaki Inoue

18 April 2023 in Journal of Clinical Medicine
Verified
Journal Article
Open access
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YKYasuaki Koyama
Yasuaki Koyama
AOAkira Ouchi
Akira Ouchi
NSNobutake Shimojo
Nobutake Shimojo
YIYoshiaki Inoue
Yoshiaki Inoue
We compared the changes in cerebral oxygen saturation (ScO2) levels during cardiac arrest (CA) events using porcine models of ventricular fibrillation CA (VF-CA) and asphyxial CA (A-CA). Twenty female pigs were randomly divided into VF-CA and A-CA groups. We initiated cardiopulmonary resuscitation (CPR) 4 min after CA and measured the cerebral tissue oxygenation index (TOI) using near-infrared spectroscopy (NIRS) before, during, and after CPR. In both groups, the TOI was the lowest at 3–4 min after pre-CPR phase initiation (VF-CA group: 3.4 min [2.8–3.9]; A-CA group: 3.2 min [2.9–4.6]; p = 0.386). The increase in TOI differed between the groups in the CPR phase (p < 0.001); it increased more rapidly in the VF-CA group (16.6 [5.5–32.6] vs. 1.1 [0.6–3.3] %/min; p < 0.001). Seven pigs surviving for 60 min after the return of spontaneous circulation in the VF-CA group recovered limb movement, whereas only one in the A-CA group (p = 0.023) achieved movement recovery. The increase in the TOI did not differ significantly between the groups in the post-CPR phase (p = 0.341). Therefore, it is better to monitor ScO2 concomitantly with CPR initiation using NIRS to assess the responsiveness to CPR in clinical settings.