記述言語：英語   掲載種別：研究論文（学術雑誌）  

Opioid usage for pain therapy is limited by its undesirable clinical effects, including paradoxical hyperalgesia, also known as opioid-induced hyperalgesia (OIH). However, the mechanisms associated with the development and maintenance of OIH remain unclear. Here, we investigated the effect of serotonin inhibition by the 5-HT3 receptor antagonist, ondansetron (OND), as well as serotonin deprivation via its synthesis inhibitor para-chlorophenylalanine, on mouse OIH models, with particular focus on astrocyte activation. Co-administering of OND and morphine, in combination with serotonin depletion, inhibited mechanical hyperalgesia and astrocyte activation in the spinal dorsal horn of mouse OIH models. Although previous studies have suggested that activation of astrocytes in the spinal dorsal horn is essential for the development and maintenance of OIH, herein, treatment with carbenoxolone (CBX), a gap junction inhibitor that suppresses astrocyte activation, did not ameliorate mechanical hyperalgesia in mouse OIH models. These results indicate that serotonin in the spinal dorsal horn, and activation of the 5-HT3 receptor play essential roles in OIH induced by chronic morphine, while astrocyte activation in the spinal dorsal horn serves as a secondary effect of OIH. Our findings further suggest that serotonergic regulation in the spinal dorsal horn may be a therapeutic target of OIH. PERSPECTIVE: The current study revealed that the descending serotonergic pain-facilitatory system in the spinal dorsal horn is crucial in OIH, and that activation of astrocytes is a secondary phenotype of OIH. Our study offers new therapeutic targets for OIH and may help reduce inappropriate opioid use.

DOI： 10.1016/j.jpain.2020.12.008

PubMed

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1113/JP277615

PubMed

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：WILEY-BLACKWELL  

We evaluated an alternative technique for ultrasound-guided proximal level obturator nerve block that might facilitate needle visualisation using in-plane ultrasound guidance. Twenty patients undergoing transurethral bladder tumour resection requiring an obturator nerve block were enrolled into a prospective observational study. With the patient in the lithotomy position, the transducer was placed on the medial thigh along the extended line of the inguinal crease, and aimed cephalad to view a thick fascia between the pectineus and obturator externus muscles that contains the obturator nerve. A stimulating nerve block needle was inserted at the pubic region and advanced in-plane with the transducer in an anterior-to-posterior direction. Eight ml levobupivacaine 0.75% was injected within the fascia. The median (IQR [range]) duration for ultrasound identification of the target and injection were 8.5 (7-12 [5-24]) s and 62 (44.5-78.25 [39-383]) s, respectively. All blocks were successful. A cadaver evaluation demonstrated that the dye injected into the target fascia using our technique travelled retrogradely through the obturator canal, and surrounded the anterior and posterior branches of the obturator nerve both proximally and distally to the obturator canal. We believe that this is a promising new technique for ultrasound-guided proximal level obturator nerve block.

DOI： 10.1111/anae.13336

Web of Science

PubMed

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記述言語：日本語   出版者・発行元：日本臨床麻酔学会  

声門近傍を占拠する喉頭乳頭腫を発症した5歳男児の麻酔を経験した.喉頭乳頭腫は嗄声や呼吸困難などの症状出現時,声門を閉塞するほど巨大化していることが多く,しばしば呼吸管理や気道確保法に難渋する.本症例では手術5日前のファイバー所見から右側臥位,喉頭展開による気管挿管が可能と判断されたが,短期間での腫瘍の急速な増大によって手技変更を余儀なくされ,結果的に気管支ファイバー挿管によって気道確保し得た.本疾患は,進行や再発による繰り返しの手術が必要となる.毎回の手術前の入念な気道評価とそれに基づいた麻酔計画の立案が重要である.また,気道確保の際には耳鼻咽喉科医と密な連携を取り,周到な準備が求められる.(著者抄録)

DOI： 10.2199/jjsca.32.791

CiNii Article

CiNii Books

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その他リンク： http://search.jamas.or.jp/link/ui/2013034782

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