{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,9]],"date-time":"2026-07-09T22:53:46Z","timestamp":1783637626860,"version":"3.55.0"},"reference-count":45,"publisher":"BMJ","issue":"2","content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":["Reg Anesth Pain Med"],"accepted":{"date-parts":[[2024,12,17]]},"published-print":{"date-parts":[[2026,2]]},"abstract":"<jats:sec>\n                    <jats:title>Background\/importance<\/jats:title>\n                    <jats:p>Local anesthetic (LA) mixtures are used in peripheral nerve blocks (PNB) to improve onset, though study results remain conflicting.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Objective<\/jats:title>\n                    <jats:p>This systematic review and meta-analysis compared the efficacy outcomes of long-acting LA to their mixture with shorter-acting LA in ultrasound-guided PNB. The primary outcome was sensory block onset.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Evidence review<\/jats:title>\n                    <jats:p>We searched WoS, Scopus, MEDLINE, EMBASE, BVS\/LILACS, and Cochrane databases from 1998 to 2024 for randomized controlled trials (RCTs). We conducted a random-effects meta-analysis, evaluated the risk of bias (RoB) with RoB 2.0, performed sensitivity analyses, assessed non-reporting bias with DOI plots and Luis Furuya-Kanamori index, and evaluated strength of evidence with Grading of Recommendations Assessment, Development and Evaluations.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Findings<\/jats:title>\n                    <jats:p>\n                      We included 10 RCTs (516 participants). Mixture of LA may have no effect on sensory block onset (mean difference (MD) \u22121.62\u2009min, 95%\u2009CI: \u22124.04 to 0.81; I\n                      <jats:sup>2<\/jats:sup>\n                      =81.50%, 95%\u2009CI: 62.82% to 90.80%; prediction interval (PI)=\u22127.78\u2009to 4.55; very low certainty) and motor block onset (MD \u22125.60\u2009min; 95%\u2009CI: \u221214.54 to 3.33, I\n                      <jats:sup>2<\/jats:sup>\n                      =98.89%, 95%\u2009CI: 98.50% to 99.18%; PI=\u221231.90\u2009to 20.69; very low certainty), while it may reduce the duration of sensory block (MD \u22122.16\u2009hours, 95%\u2009CI: \u22124.16 to \u22120.17; I\n                      <jats:sup>2<\/jats:sup>\n                      =90.77%, 95%\u2009CI: 84.22% to 94.60%; PI=\u22127.24\u2009to 2.92; very low certainty).\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>LA mixtures may not affect sensory and motor block onset in ultrasound-guided PNB but could shorten the duration of sensory blockade.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1136\/rapm-2024-106104","type":"journal-article","created":{"date-parts":[[2025,1,8]],"date-time":"2025-01-08T12:20:14Z","timestamp":1736338814000},"page":"132-141","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":9,"title":["Efficacy of long-acting local anesthetics versus their mixture with shorter-acting local anesthetics for peripheral nerve blocks guided by ultrasound: a systematic review with meta-analysis of randomized controlled trials"],"prefix":"10.1136","volume":"51","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-4640-7178","authenticated-orcid":false,"given":"Natanael","family":"Pietroski dos Santos","sequence":"first","affiliation":[{"name":"FMABC University Center, Santo Andr\u00e9, SP, 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Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1001-1948","authenticated-orcid":false,"given":"Vanessa Henriques","family":"Carvalho","sequence":"additional","affiliation":[{"name":"State University of Campinas, Campinas, SP, Brazil"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"239","published-online":{"date-parts":[[2025,1,8]]},"reference":[{"key":"2026020508450689000_51.2.132.1","doi-asserted-by":"publisher","DOI":"10.1213\/ane.0b013e31819237f8"},{"key":"2026020508450689000_51.2.132.2","doi-asserted-by":"crossref","first-page":"542","DOI":"10.3906\/sag-1207-22","article-title":"The effect of addition of lidocaine to bupivacaine on anesthesia beginning time, block time, and block quality in lateral sagittal infraclavicular block","volume":"43","author":"\u00d6zmen","year":"2013","journal-title":"Turk J Med Sci"},{"key":"2026020508450689000_51.2.132.3","first-page":"229","article-title":"Addition of clonidine 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