{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,14]],"date-time":"2026-01-14T16:11:12Z","timestamp":1768407072120,"version":"3.49.0"},"reference-count":7,"publisher":"BMJ","issue":"3","funder":[{"name":"Region Zealand Research Foundation"},{"DOI":"10.13039\/501100022183","name":"DASAIM","doi-asserted-by":"crossref","id":[{"id":"10.13039\/501100022183","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":["bmj.com"],"crossmark-restriction":true},"short-container-title":[],"accepted":{"date-parts":[[2018,10,10]]},"published-print":{"date-parts":[[2019,3]]},"abstract":"<jats:sec>\n                  <jats:title>Background<\/jats:title>\n                  <jats:p>We tested the joint hypotheses that both perineural and systemic dexmedetomidine prolong the duration of an ulnar nerve block (UNB) compared with ropivacaine alone and that systemic dexmedetomidine is noninferior compared with perineural dexmedetomidine in block prolongation.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Methods<\/jats:title>\n                  <jats:p>We performed bilateral UNBs in 22 healthy volunteers on two separate days. On the first day, each arm was randomized to either 4\u2009mL ropivacaine 5\u2009mg\/mL+1\u2009mL dexmedetomidine 100\u2009\u00b5g\/mL (Perineural) or 4\u2009mL ropivacaine 5\u2009mg\/mL+1\u2009mL saline (Systemic). On the subsequent treatment day, each arm was randomized to 1\u2009mL of saline plus 4\u2009mL of ropivacaine at either 7.5\u2009mg\/mL(HiRopi) or 5\u2009mg\/mL (NoDex). The primary outcome measure was the duration of sensory block assessed by mechanical discrimination.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Results<\/jats:title>\n                  <jats:p>Mean sensory block duration was longer in both the Perineural (14.4\u2009hours, 95% CI 13.1 to 15.6) and Systemic treatments (9.2\u2009hours, 95%\u2009CI 8.6 to 9.8) compared with the NoDex treatment (7.1\u2009hours, 95%\u2009CI 6.6 to 7.6) (p&lt;0.0001\u2009for both). Systemic dexmedetomidine was inferior (not noninferior) compared with perineural dexmedetomidine, as the 95%\u2009CI of the difference (mean difference 5.2\u2009hour, 95%\u2009CI 4.2 to 6.1) exceeded the noninferiority limit of 3.6\u2009hour. Onset time did not differ among the groups. The other test modalities demonstrated similar block durations as the primary outcome.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Conclusions<\/jats:title>\n                  <jats:p>Adding dexmedetomidine perineurally to ropivacaine doubles the duration of an UNB. Systemic dexmedetomidine also prolongs the duration of UNB, but has less of an effect compared with the perineural route.<\/jats:p>\n               <\/jats:sec>\n               <jats:sec>\n                  <jats:title>Trial registration number<\/jats:title>\n                  <jats:p>\n                     <jats:ext-link xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" ext-link-type=\"clintrialgov\" xlink:href=\"NCT03222323\">NCT03222323<\/jats:ext-link>.<\/jats:p>\n               <\/jats:sec>","DOI":"10.1136\/rapm-2018-100089","type":"journal-article","created":{"date-parts":[[2019,1,25]],"date-time":"2019-01-25T06:27:41Z","timestamp":1548397661000},"page":"333-340","update-policy":"https:\/\/doi.org\/10.1136\/crossmarkpolicy","source":"Crossref","is-referenced-by-count":23,"title":["Systemic dexmedetomidine is not as efficient as perineural dexmedetomidine in prolonging an ulnar nerve block"],"prefix":"10.1136","volume":"44","clinical-trial-number":[{"clinical-trial-number":"nct03222323","registry":"10.18810\/clinical-trials-gov"},{"clinical-trial-number":"nct03222323","registry":"10.18810\/clinical-trials-gov"}],"author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1402-8162","authenticated-orcid":false,"given":"Jakob Hessel","family":"Andersen","sequence":"first","affiliation":[{"name":"Department of Anesthesiology, Zealand University Hospital, Koege, Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Pia","family":"Jaeger","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology, Rigshospitalet, Kobenhavn, Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ulrik","family":"Grevstad","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology, Gentofte Hospital, Hellerup, Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Stine","family":"Estrup","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology, Zealand University Hospital, Koege, Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Anja","family":"Geisler","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology, Zealand University Hospital, Koege, Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Frederik","family":"Vilhelmsen","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology, Zealand University Hospital, Koege, Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jorgen B","family":"Dahl","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology, Bispebjerg Hospital, Kobenhavn, Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Gunnar Hellmund","family":"Laier","sequence":"additional","affiliation":[{"name":"Production Research and Innovation, Region Zealand, Soroe, Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6144-3273","authenticated-orcid":false,"given":"Brian M","family":"Ilfeld","sequence":"additional","affiliation":[{"name":"Division of Regional Anesthesia and Acute Pain Medicine, Department of Anesthesiology, University of California, San Diego, La Jolla, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ole","family":"Mathiesen","sequence":"additional","affiliation":[{"name":"Department of Anesthesiology, Zealand University Hospital, Koege, Denmark"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"239","published-online":{"date-parts":[[2019,1,23]]},"reference":[{"key":"2025101109531089000_44.3.333.1","doi-asserted-by":"publisher","DOI":"10.1093\/bja\/aew411"},{"key":"2025101109531089000_44.3.333.2","doi-asserted-by":"publisher","DOI":"10.1093\/bja\/aes400"},{"key":"2025101109531089000_44.3.333.3","doi-asserted-by":"crossref","first-page":"683","DOI":"10.1097\/ALN.0000000000000983","article-title":"IV and perineural dexmedetomidine similarly prolong the duration of analgesia after interscalene brachial plexus block: a randomized, three-arm, triple-masked, placebo-controlled trial","volume":"124","author":"Abdallah","year":"2016","journal-title":"Anesthesiology"},{"key":"2025101109531089000_44.3.333.4","doi-asserted-by":"crossref","first-page":"790","DOI":"10.1097\/EJA.0000000000000246","article-title":"A pharmacodynamic evaluation of dexmedetomidine as an additive drug to ropivacaine for peripheral nerve blockade: a randomised, triple-blind, controlled study in volunteers","volume":"32","author":"Keplinger","year":"2015","journal-title":"Eur J Anaesthesiol"},{"key":"2025101109531089000_44.3.333.5","doi-asserted-by":"crossref","first-page":"66","DOI":"10.1097\/ALN.0000000000001429","article-title":"Does dexmedetomidine have a perineural mechanism of action when used as an adjuvant to ropivacaine?","volume":"126","author":"Andersen","year":"2017","journal-title":"Anesthesiology"},{"key":"2025101109531089000_44.3.333.6","doi-asserted-by":"crossref","DOI":"10.1136\/bmj.c869","article-title":"Consort 2010 explanation and elaboration: updated guidelines for reporting parallel group randomised trials","volume":"340","author":"Moher","year":"2010","journal-title":"BMJ"},{"key":"2025101109531089000_44.3.333.7","doi-asserted-by":"publisher","DOI":"10.1097\/AAP.0000000000000033"}],"container-title":["Regional Anesthesia &amp; Pain Medicine"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/syndication.highwire.org\/content\/doi\/10.1136\/rapm-2018-100089","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T16:53:17Z","timestamp":1760201597000},"score":1,"resource":{"primary":{"URL":"https:\/\/rapm.bmj.com\/lookup\/doi\/10.1136\/rapm-2018-100089"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,1,23]]},"references-count":7,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2019,2,18]]},"published-print":{"date-parts":[[2019,3]]}},"alternative-id":["10.1136\/rapm-2018-100089"],"URL":"https:\/\/doi.org\/10.1136\/rapm-2018-100089","relation":{},"ISSN":["1098-7339","1532-8651"],"issn-type":[{"value":"1098-7339","type":"print"},{"value":"1532-8651","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,1,23]]}}}