{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,23]],"date-time":"2026-10-23T20:27:50Z","timestamp":1792787270242,"version":"4.5.0"},"reference-count":33,"publisher":"BMJ","issue":"11","license":[{"start":{"date-parts":[[2024,11,1]],"date-time":"2024-11-01T00:00:00Z","timestamp":1730419200000},"content-version":"unspecified","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc\/4.0\/"}],"funder":[{"name":"Zhejiang Health Science and Technology Planning Project","award":["2021KY768"],"award-info":[{"award-number":["2021KY768"]}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["81870868"],"award-info":[{"award-number":["81870868"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["BMJ Open"],"accepted":{"date-parts":[[2024,10,9]]},"published-print":{"date-parts":[[2024,11]]},"abstract":"<jats:sec>\n                    <jats:title>Objective<\/jats:title>\n                    <jats:p>\n                      To investigate the efficacy of esketamine as an adjuvant to epidural ropivacaine for labour analgesia by determining its effect on the median effective concentration (EC\n                      <jats:sub>50<\/jats:sub>\n                      ) in a 20\u2009ml volume of ropivacaine.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Design<\/jats:title>\n                    <jats:p>A prospective, double-blind dose-response study.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Setting<\/jats:title>\n                    <jats:p>This study was conducted in Women\u2019s Hospital, School of Medicine, Zhejiang University, China.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Participants<\/jats:title>\n                    <jats:p>\n                      One hundred and fifty parturients who requested epidural analgesia were recruited in this study to randomly receive epidural ropivacaine alone or with esketamine of 0.2 mg ml\n                      <jats:sup>\u22121<\/jats:sup>\n                      , 0.3 mg ml\n                      <jats:sup>\u22121<\/jats:sup>\n                      , 0.4 mg ml\n                      <jats:sup>\u22121<\/jats:sup>\n                      or 0.5 mg ml\n                      <jats:sup>\u22121<\/jats:sup>\n                      , respectively.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Primary and secondary outcome measures<\/jats:title>\n                    <jats:p>\n                      The primary outcome, EC\n                      <jats:sub>50<\/jats:sub>\n                      of ropivacaine, was determined using an up-down sequential allocation technique. The secondary outcomes were analgesia characteristics, Ramsay Sedation Scale score, labour duration, caesarean section rate and adverse effects.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      The EC\n                      <jats:sub>50<\/jats:sub>\n                      of ropivacaine with the addition of esketamine at concentrations of 0.3\u2009mg ml\n                      <jats:sup>\u22121<\/jats:sup>\n                      , 0.4\u2009mg ml\n                      <jats:sup>\u22121<\/jats:sup>\n                      and 0.5\u2009mg ml\n                      <jats:sup>\u22121<\/jats:sup>\n                      resulted in significant reductions in the EC\n                      <jats:sub>50<\/jats:sub>\n                      of ropivacaine to 0.050%, 0.044% and 0.043%, respectively, from baseline (esketamine 0 mg ml\n                      <jats:sup>\u22121<\/jats:sup>\n                      ) (p&lt;0.0001). However, reductions of the EC\n                      <jats:sub>50<\/jats:sub>\n                      of ropivacaine were similar among the groups with esketamine of 0.3 mg ml\n                      <jats:sup>\u22121<\/jats:sup>\n                      , 0.4 mg ml\n                      <jats:sup>\u22121<\/jats:sup>\n                      and 0.5 mg ml\n                      <jats:sup>\u22121<\/jats:sup>\n                      (p&gt;0.05). The Ramsay Sedation Scale score was higher and more dizziness was observed in the Group of esketamine 0.5 mg ml\n                      <jats:sup>\u22121<\/jats:sup>\n                      compared with all other groups (p&lt;0.0001). During the peripartum period, no differences in sensory blockade level, Bromage score, labour duration and percentage of caesarean delivery were found among the groups.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>\n                      Under the conditions of this study, the addition of epidural esketamine of 0.3\u2009mg\u22c5mL\n                      <jats:sup>\u22121<\/jats:sup>\n                      , 0.4\u2009mg\u22c5mL\n                      <jats:sup>\u22121<\/jats:sup>\n                      and 0.5\u2009mg\u22c5mL\n                      <jats:sup>\u22121<\/jats:sup>\n                      offered a similar ropivacaine dose-sparing effect; 0.5\u2009mg\u22c5mL\n                      <jats:sup>\u22121<\/jats:sup>\n                      of esketamine produced more adverse effects.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Trial registration number<\/jats:title>\n                    <jats:p>ChiCTR2100054348.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1136\/bmjopen-2023-071818","type":"journal-article","created":{"date-parts":[[2024,11,2]],"date-time":"2024-11-02T23:05:26Z","timestamp":1730588726000},"page":"e071818","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":5,"title":["Esketamine administered epidurally as an adjuvant to epidural ropivacaine for labour analgesia: a prospective, double-blind dose-response study"],"prefix":"10.1136","volume":"14","author":[{"given":"Lili","family":"Xu","sequence":"first","affiliation":[{"name":"Department of Anesthesia, Women\u2019s Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shuxi","family":"Li","sequence":"additional","affiliation":[{"name":"Department of Anesthesia, Women\u2019s Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chenghong","family":"Zhang","sequence":"additional","affiliation":[{"name":"Department of Anesthesia, Women\u2019s Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yanhong","family":"Zhou","sequence":"additional","affiliation":[{"name":"Department of Anesthesia, Women\u2019s Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9219-1681","authenticated-orcid":false,"given":"Xinzhong","family":"Chen","sequence":"additional","affiliation":[{"name":"Department of Anesthesia, Women\u2019s Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2024,11,2]]},"reference":[{"key":"2025121600110069000_14.11.e071818.1","doi-asserted-by":"crossref","first-page":"356","DOI":"10.1002\/ijgo.14175","article-title":"Epidural analgesia in labor: A narrative review","volume":"159","author":"Halliday","year":"2022","journal-title":"Int J Gynaecol Obstet"},{"key":"2025121600110069000_14.11.e071818.2","article-title":"Epidural versus non-epidural or no analgesia for pain management in labour","volume":"5","author":"Anim-Somuah","year":"2018","journal-title":"Cochrane Database Syst 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Bethesda (MD): National Library of Medicine (US), 2019."}],"container-title":["BMJ Open"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/bmjopen-2023-071818","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,12,16]],"date-time":"2025-12-16T08:11:20Z","timestamp":1765872680000},"score":1,"resource":{"primary":{"URL":"https:\/\/bmjopen.bmj.com\/lookup\/doi\/10.1136\/bmjopen-2023-071818"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2024,11]]},"references-count":33,"journal-issue":{"issue":"11","published-online":{"date-parts":[[2024,11,2]]},"published-print":{"date-parts":[[2024,11]]}},"alternative-id":["10.1136\/bmjopen-2023-071818"],"URL":"https:\/\/doi.org\/10.1136\/bmjopen-2023-071818","relation":{},"ISSN":["2044-6055","2044-6055"],"issn-type":[{"value":"2044-6055","type":"print"},{"value":"2044-6055","type":"electronic"}],"subject":[],"published":{"date-parts":[[2024,11]]}}}