Education 【 display / non-display 】

Education 【 display / non-display 】

• 2015

  -

  2019

  Sapporo Medical University   Graduate School of Medicine  

• 2010

  -

  2016

  Sapporo Medical University   医学部   医学科  

Research Experience 【 display / non-display 】

Research Experience 【 display / non-display 】

• 2024.03

  -

  Now

  University of California San Francisco   Department of Anesthesia and Perioperative Care   Postdoctral Scholar

• 2021.08

  -

  Now

  Sapporo Medical University   Department of anesthesiology   Assistant professor

  MD. PhD.

• 2018.04

  -

  2020.07

  Hokkaido Medical Center for Child Health and Rehabilitation   Department of anesthesiology   診療医

  MD. PhD.

• 2015.04

  -

  2018.03

  Sapporo Medical University   Department of anesthesiology   Doctor

  MD

Research Areas 【 display / non-display 】

Research Areas 【 display / non-display 】

• Life sciences   Anesthesiology  

Affiliation 【 display / non-display 】

Affiliation 【 display / non-display 】

• Sapporo Medical University   Department of anesthesiology   Assistant professor   MD. Ph.D  

Research Interests 【 display / non-display 】

Research Interests 【 display / non-display 】

• gut-brain axis

• Airway management

• Pediatric anesthesia

• Anesthesiology

• Neurosurgical anesthesia

Papers 【 display / non-display 】

Papers 【 display / non-display 】

• Gut Microbiota Influences Developmental Anesthetic Neurotoxicity in Neonatal Rats.

  Tomohiro Chaki, Yuri Horiguchi, Shunsuke Tachibana, Satoshi Sato, Tomoki Hirahata, Noriaki Nishihara, Natsumi Kii, Yusuke Yoshikawa, Kengo Hayamizu, Michiaki Yamakage

  Anesthesia and analgesia    2025.02  [International journal]

  Authorship：   Lead author  , Corresponding author

  　View Summary

  BACKGROUND: Anesthetic exposure during childhood is significantly associated with impairment of neurodevelopmental outcomes; however, the causal relationship and detailed mechanism of developmental anesthetic neurotoxicity remain unclear. Gut microbiota produces various metabolites and influences the brain function and development of the host. This relationship is referred to as the gut-brain axis. Gut microbiota may influence developmental anesthetic neurotoxicity caused by sevoflurane exposure. This study investigated the effect of changes in the composition of gut microbiota after fecal microbiota transplantation on spatial learning disability caused by developmental anesthetic neurotoxicity in neonatal rats. METHODS: Neonatal rats were allocated into the Control (n = 10) and Sevo (n = 10) groups in Experiment 1 and the Sevo (n = 20) and Sevo+FMT (n = 20) groups in Experiment 2, according to the randomly allocated mothers' group. The rats in Sevo and Sevo+FMT groups were exposed to 2.1% sevoflurane for 2 hours on postnatal days 7 to 13. Neonatal rats in the Sevo+FMT group received fecal microbiota transplantation immediately after sevoflurane exposure on postnatal days 7 to 13. The samples for fecal microbiota transplantation were obtained from nonanesthetized healthy adult rats. Behavioral tests, including Open field, Y-maze, Morris water maze, and reversal Morris water maze tests, were performed to evaluate spatial learning ability on postnatal days 26 to 39. RESULTS: Experiment 1 revealed that sevoflurane exposure significantly altered the gut microbiota composition. The relative abundance of Roseburia (effect value: 1.01) and Bacteroides genus (effect value: 1.03) increased significantly after sevoflurane exposure, whereas that of Lactobacillus (effect value: -1.20) decreased significantly. Experiment 2 revealed that fecal microbiota transplantation improved latency to target (mean ± SEM; Sevo group: 9.7 ± 8.2 seconds vs, Sevo+FMT group: 2.7 ± 2.4 seconds, d=1.16, 95% confidence interval: -12.7 to -1.3 seconds, P = .019) and target zone crossing times (Sevo group: 2.4 ± 1.6 vs, Sevo+FMT group: 5.4 ± 1.4, d=1.99, 95% confidence interval: 2.0-5.0, P < .001) in the reversal Morris water maze test. Microbiota analysis revealed that the α-diversity of gut microbiota increased after fecal microbiota transplantation. Similarly, the relative abundance of the Firmicutes phylum (effect value: 1.44), Ruminococcus genus (effect value: 1.69), and butyrate-producing bacteria increased after fecal microbiota transplantation. Furthermore, fecal microbiota transplantation increased the fecal concentration of butyrate and induced histone acetylation and the mRNA expression of brain-derived neurotrophic factor in the hippocampus, thereby suppressing neuroinflammation and neuronal apoptosis. CONCLUSIONS: The alternation of gut microbiota after fecal microbiota transplantation influenced spatial learning ability in neonatal rats with developmental anesthetic neurotoxicity. Modulation of the gut microbiota may be an effective prophylaxis for developmental anesthetic neurotoxicity in children.

  DOI PubMed

• Differences in circulating blood volume changes during emergence from general anesthesia in transcatheter aortic valve implantation and MitraClip implantation.

  Makishi Maeda, Yusuke Yoshikawa, Sho Ohno, Tomohiro Chaki, Michiaki Yamakage

  Journal of anesthesia   38 ( 4 ) 489 - 495  2024.08  [Domestic journal]

  　View Summary

  PURPOSE: We aimed to compare changes in the circulating blood volume (CBV) during emergence from general anesthesia in patients undergoing transcatheter aortic valve implantation (TAVI) and MitraClip implantation. METHOD: We included 97 patients who underwent TAVI or MitraClip implantation. The primary outcome was the rate of change in the estimated CBV associated with emergence from general anesthesia. The secondary outcomes were hemoglobin and hematocrit values before and after emergence from anesthesia for each procedure. Additionally, the independent factors associated with changes in the estimated CBV were assessed using multiple regression analysis. RESULTS: In the TAVI group, the hemoglobin concentration increased from 9.6 g/dL before emergence from anesthesia to 10.8 g/dL after emergence (P < 0.001; mean difference, 1.2 g/dL, 95% confidence interval [CI] 1.1-1.3 g/dL). Conversely, no statistically significant change was observed in the hemoglobin concentration before and after emergence from anesthesia in the MitraClip group. The mean rate of change in the estimated CBV was - 15.4% (standard deviation [SD] 6.4%) in the TAVI group and - 2.4% (SD, 4.7%) in the MitraClip group, indicating a significant decrease in the estimated CBV in the former than in the latter (P < 0.001; mean difference, 13.0%; 95% CI 9.9-16.1%). CONCLUSION: Emergence from general anesthesia increased the hemoglobin concentration and decreased the estimated CBV in patients undergoing TAVI but did not elicit significant changes in patients undergoing MitraClip implantation. These results may provide a rationale for minimizing blood transfusions during general anesthesia in patients undergoing these procedures.

  DOI PubMed

• INJEX50 could improve the success rate of local anesthesia for arterial cannulation in the pediatric intensive care unit: A randomized, double-blind, single-center study.

  Wataru Sakai, Tomohiro Chaki, Shunsuke Tachibana, Yuki Ichisaka, Yuko Nawa, Tomohiro Nawa, Michiaki Yamakage

  Paediatric anaesthesia    2024.05  [International journal]

  　View Summary

  BACKGROUND: Quick arterial cannulation is required in pediatric emergency situation, which require effective local anesthesia to avoid withdrawal movement. However, pediatric local anesthesia could be difficult because of withdrawal movement. Jet injectors, which are needleless and provide local anesthesia quickly, could be helpful for pediatric local anesthesia during arterial cannulation. AIMS: This study aimed to examine whether new jet injector "INJEX50" could improve the success rate of local anesthesia for arterial cannulation in pediatric intensive care unit compared with the current standard of care, infiltration using a 26-gauge needle. METHODS: This study was a randomized, double-blind, single-center study. Participants were infants and young children in the pediatric intensive care unit, who required an arterial line. Local anesthesia was performed with either a 26-gauge needle (group C) or INJEX50 (group I) before arterial cannulation. The primary outcome (success of local anesthesia) was the presence of withdrawal movement at the time of skin puncture for arterial cannulation. The secondary outcomes included rescue sedation during arterial cannulation. Data were analyzed using Fisher's exact test and the Mann-Whitney U-test, with values of p < .05 considered statistically significant. RESULTS: Seventy patients were randomly assigned to groups C and I. The local anesthesia success rate in group I (30/35 [86%]) was significantly higher than that in group C (15/35 [43%], odds ratio, 8.00; 95% confidence interval, 2.51-25.5; p = .0005). In conclusion, INJEX50 could improve success rate of local anesthesia for arterial cannulation in pediatric intensive care unit compared with 26-gauge needle.

  DOI PubMed

• Comparison of the negative effect of remimazolam and propofol on cardiac contractility: Analysis of a randomised parallel-group trial and a preclinical ex vivo study.

  Yusuke Yoshikawa, Shunsuke Oura, Masatoshi Kanda, Tomohiro Chaki, Naoyuki Hirata, Mitsutaka Edanaga, Michiaki Yamakage

  Clinical and experimental pharmacology & physiology   51 ( 3 ) e13840  2024.03  [International journal]

  　View Summary

  Remimazolam is a newly developed ultra-short-acting benzodiazepine that exerts sedative effects. This study aimed to clarify the effects of remimazolam on cardiac contractility. In a randomised-parallel group trial, haemodynamic parameters were compared between propofol (n = 11) and remimazolam (n = 12) groups during the induction of general anaesthesia in patients undergoing non-cardiac surgery. In a preclinical study, the direct effects of remimazolam on cardiac contractility were also evaluated using isolated rat hearts. RNA sequence data obtained from rat and human hearts were analysed to assess the expression patterns of the cardiac γ-aminobutyric acid type A (GABAA ) receptor subunits. In a clinical study, the proportional change of the maximum rate of arterial pressure rise was milder during the study period in the remimazolam group (propofol: -52.6 [10.2] (mean [standard deviation])% vs. remimazolam: -39.7% [10.5%], p = 0.007). In a preclinical study, remimazolam did not exert a negative effect on left ventricle developed pressure, whereas propofol did exert a negative effect after bolus administration of a high dose (propofol: -26.9% [3.5%] vs. remimazolam: -1.1 [6.9%], p < 0.001). Analysis of the RNA sequence revealed a lack of γ subunits, which are part of the major benzodiazepine binding site of the GABAA receptor, in rat and human hearts. These results indicate that remimazolam does not have a direct negative effect on cardiac contractility, which might contribute to its milder effect on cardiac contractility during the induction of general anaesthesia. The expression patterns of cardiac GABAA receptor subunits might be associated with the unique pharmacokinetics of benzodiazepines in the heart.

  DOI PubMed

• Comparing leak pressure of LMA® ProSeal™ versus i-gel® at head rotation: a randomized controlled trial.

  Tomohiro Chaki, Masatsugu Koizumi, Shunsuke Tachibana, Tomomi Matsumoto, Tomoe Kumagai, Yuki Hashimoto, Michiaki Yamakage

  Canadian journal of anaesthesia = Journal canadien d'anesthesie    2023.11  [Refereed]  [International journal]

  Authorship：   Lead author  , Corresponding author

  　View Summary

  PURPOSE: The effect of head rotation on supraglottic airway (SGA) oropharyngeal leak pressure (OPLP) has not been well elucidated. The aim of this study was to help clarify which SGA device provides higher OPLP at head-rotated position. METHODS: Patients who underwent elective surgery under general anesthesia were enrolled and randomly divided into laryngeal mask airway (LMA®) ProSeal™ and i-gel® groups. The allocated SGA device was inserted under anesthesia. The primary outcome was OPLP, and secondary outcomes were ventilation score, expiratory tidal volume, and maximum pressure under volume-controlled ventilation (VCV) with an inspiratory tidal volume of 10 mL·kg-1 ideal body weight and fibreoptic view of the vocal cords at 0°, 30°, and 60° head rotation. RESULTS: Data from 78 and 76 patients were analyzed in the LMA ProSeal and i-gel groups, respectively. The mean (standard deviation) OPLP of the LMA ProSeal was significantly higher than that of the i-gel at the 60° head-rotated position (LMA ProSeal, 20.4 [6.5] vs i-gel, 16.9 [7.8] cm H2O; difference in means, 3.6; adjusted 95% confidence interval, 0.5 to 6.6; adjusted P = 0.02, adjusted for six comparisons). The maximum pressure under VCV at 60° head rotation was significantly higher in the LMA ProSeal group than in the i-gel group. The expiratory tidal volume of the LMA ProSeal did not significantly change with head rotation and was significantly higher than that of the i-gel at 60° head rotation. Ventilation score, fibreoptic view of the vocal cords, and complications were not significantly different between the ProSeal and i-gel groups. CONCLUSIONS: The LMA ProSeal provides higher OPLP than the i-gel at a 60° head-rotated position under general anesthesia. TRIAL REGISTRATION: Japan Registry of Clinical Trials (https://jrct.niph.go.jp) (JRCT1012210043); registered 18 October 2021.

  DOI PubMed

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Misc 【 display / non-display 】

Misc 【 display / non-display 】

• 限局性の下行大動脈解離が生じたバルーン大動脈弁形成術(BAV)の1症例

  佐藤慧, 吉川裕介, 茶木友浩, 枝長充隆, 山蔭道明

  Cardiovascular Anesthesia   21 ( Suppl )  2017

  J-GLOBAL

• 超高齢者における経カテーテル大動脈弁植え込み術の一症例

  前田真岐志, 枝長充隆, 茶木友浩, 立花俊祐, 吉川裕介, 山蔭道明

  Cardiovascular Anesthesia   20 ( Suppl )  2016

  J-GLOBAL

• デクスメデトミジンは高血圧性肥大心筋においても直接心筋保護作用を保持する

  吉川裕介, 平田直之, 川口亮一, 宮下龍, 丸山大介, 茶木友浩, 山蔭道明

  Cardiovascular Anesthesia   19 ( Suppl )  2015

  J-GLOBAL

• 局所麻酔薬の頭皮下投与後の血中濃度

  山下 美妃, 向 祐志, 戸田 貴大, 猪爪 信夫, 郡 修徳, 茶木 友浩, 杉野 繁一, 早瀬 知, 山蔭 道明

  臨床薬理 ( (一社)日本臨床薬理学会 )  45 ( Suppl. ) S267 - S267  2014.11

Awards 【 display / non-display 】

Awards 【 display / non-display 】

• Young encouragement award

  2021.06   Japanese Society of Anesthesiologists   Head Rotation Reduces Oropharyngeal Leak Pressure of the i-gel® and LMA-SupremeTM in Paralyzed, Anesthetized Patients, A Randomized Trial

  Winner： Tomohiro Chaki, Shunsuke Tachibana, Sho Kumita, Honami Sato, Kosuke Hamada, Michiaki Yamakage

• Best presentation award

  2017.09   Japanese Society of Anesthesiologists, Hokkaido and Tohoku   Lipid, A Solvent of Propofol, Induces Muscle Wasting via Oxidative Stress

  Winner： Tomohiro Chaki, Naoyuki Hirata, Yusuke Yoshikawa, Ryoichi Kawaguchi, Michiaki Yamakage

Research Projects 【 display / non-display 】

Research Projects 【 display / non-display 】

• 低親和性神経成長因子受容体選択的リガンド：LM11A-31による術後認知機能障害予防戦略

  基盤研究(C)

  Project Year :

  2023.04

  -

  2026.03

   

  山蔭 道明, 平畑 知輝, 茶木 友浩, 佐藤 慧

• トランスポーター機能の修飾を介した麻酔薬の胎盤移行性制御の探究

  基盤研究(C)

  Project Year :

  2022.04

  -

  2025.03

   

  佐藤 慧, 茶木 友浩

• Exploration of the prophylaxis for anesthetic-induced neurodegeneration with gut-brain axis approach in neonate

  Project Year :

  2021.04

  -

  2022.03

   

  Tomohiro Chaki

  Authorship： Principal investigator

• The influence of microbiota to neurotoxicity of general anesthesia for developing brain

  Grant-in-Aid for Early-Career Scientists

  Project Year :

  2020.04

  -

  2024.03

   

  茶木 友浩

  　View Summary

  腸内細菌叢移植による幼若脳麻酔薬神経毒性への影響を明らかにするため、セボフルラン曝露のみを行う（Sevo）群、セボフルラン曝露+腸内細菌叢移植を行う（Sevo+FMT）群にラットを割り付けた。生後28日から施行したモーリス水迷路試験およびY字迷路試験の結果、Sevo+FMT群では空間学習能力が改善する結果を認め、腸内細菌叢移植によって幼若脳麻酔薬神経毒性が軽減される可能性が示唆された。さらに、腸内細菌叢移植による実際の腸内細菌叢の変化を検証するため、生後21日のラットから糞便を採取し、16sリボソーマルRNA解析による腸内細菌叢解析を実施した。その結果、Sevo+FMT群では、Chao1 index及びSimpson indexが有意に高く、さらに門レベルでの解析では、Firmicutes門及びLentisphaerae門の細菌が増加する一方、Bacteroides門及びProteobacteria門の細菌が減少することが明らかとなった。Firmicutes門には、脳内でBDNF産生を促進する短鎖脂肪酸を産生する菌株が多く属していることが知られており、Firmicutes門の細菌増加が行動学的な学習能力改善効果をもたらしたと考えられる。今後は、短鎖脂肪酸の評価および、海馬におけるBDNF産生量、ヒストンアセチル化定量などを行い、腸内細菌叢移植が学習能力改善をもたらした機序について明らかにしていく予定である。

• The mechanism of propofol infusion syndrome - the potency of dexmedetomidine as a treatment or prevention of propofol infusion syndrome

  Grant-in-Aid for Young Scientists (B)

  Project Year :

  2017.04

  -

  2020.03

   

  Chaki Tomohiro

  　View Summary

  We used rats and infused 1% propofol and it's solvent, lipofundin for three days. The rats received propofol infusion did not express the symptoms of propofol infusion syndrome, but the rats received lipofundin expressed the elevation of creatine kinase and myoglobin indicating skeletal muscle damage. We detected that lipid peroxidation related the lipid induced skeletal muscle damage. This mechanism was validated by the phenomenon that the alpha-tocopherol, which is one of the vitamin E, suppressed the lipid induced skeletal muscle damage. We concluded that the lipid which was used as a solvent of propofol induced skeletal muscle damage via lipid peroxidation and propofol itself prevented the skeletal muscle damage by it's anti-oxidative effect. Moreover, we investigated the preventive effect of dexmedetomidine on lipid induced skeletal muscle damage, but dexmedetomidine did not have the attenuating effect of skeletal muscle damage.