{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,7,30]],"date-time":"2025-07-30T16:05:34Z","timestamp":1753891534034,"version":"3.41.2"},"reference-count":49,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2024,11,18]],"date-time":"2024-11-18T00:00:00Z","timestamp":1731888000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Med."],"abstract":"<jats:sec><jats:title>Background<\/jats:title><jats:p>Perineural administration of dexmedetomidine (PN-DEX) can enhance the efficacy of local anesthetics used in regional nerve blocks while decreasing the median effective concentration (EC50) of these anesthetics. Intranasal administration of dexmedetomidine (IN-DEX) is more accessible for sedation during regional anesthesia because of its non-invasive systemic administration and demonstrates synergism with local anesthetic. However, it remains unclear whether IN-DEX affects the EC50 of local anesthetics used in caudal blocks.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>This study was a prospective, single-center, double-blind, randomized controlled trial. Patients scheduled to undergo elective hemorrhoidectomy were included and divided into three groups. Furthermore, 0.01\u2009mL\/kg of normal saline and 1\u2009\u03bcg\/kg and 2\u2009\u03bcg\/kg of dexmedetomidine were dripped into both nostrils of the patients in groups IN-NS, IN-DEX1, and IN-DEX2, respectively. These were administered 15\u2009min before the caudal block. The initial concentration of ropivacaine was set at 0.4%, which was then varied by 0.025% using the up-and-down sequential allocation method. Vital signs, instances of hypotension and bradycardia with treatment, and other adverse reactions were recorded and compared.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>The EC50 values of ropivacaine were 0.275% (95% confidence interval (CI), 0.254\u20130.296%) in group IN-NS, 0.257% (95% CI, 0.238\u20130.276%) in group IN-DEX1, and 0.216% (95% CI, 0.195\u20130.236%) in group IN-DEX2. The EC95 values of ropivacaine were 0.315% (95% CI, 0.295\u20130.370%) in group IN-NS, 0.297% (95% CI, 0.278\u20130.351%) in group IN-DEX1, and 0.256% (95% CI, 0.236\u20130.310%) in group IN-DEX2. Compared to group IN-NS, the EC50 value of ropivacaine in IN-DEX2 was significantly decreased by 21.4% (<jats:italic>p<\/jats:italic>\u2009=\u20090.001), while there was no significant difference between group IN-NS and IN-DEX1 (<jats:italic>p<\/jats:italic>\u2009=\u20090.125). There were no differences in hypotension and bradycardia with treatment among the different groups.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>IN-DEX decreased the EC50 of ropivacaine for the caudal block, and there was a specific dose-dependent effect for IN-DEX. The side effects were similar across all groups.<\/jats:p><\/jats:sec>","DOI":"10.3389\/fmed.2024.1481938","type":"journal-article","created":{"date-parts":[[2024,11,18]],"date-time":"2024-11-18T04:23:13Z","timestamp":1731903793000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":1,"title":["A randomized double-blinded study assessing the effect of different doses of transnasal dexmedetomidine on the median effective concentration of ropivacaine for a caudal block"],"prefix":"10.3389","volume":"11","author":[{"given":"Fu","family":"Wang","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Shijie","family":"Qu","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yinglu","family":"Chen","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bo","family":"Liao","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Li","family":"Ao","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hui","family":"Zhang","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hongyan","family":"Zhou","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Liang","family":"Zhang","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2024,11,18]]},"reference":[{"key":"ref1","doi-asserted-by":"publisher","first-page":"44","DOI":"10.1111\/j.1460-9592.2011.03669.x","article-title":"Caudal blocks","volume":"22","author":"Johr","year":"2012","journal-title":"Paediatr Anaesth"},{"key":"ref2","doi-asserted-by":"publisher","first-page":"39","DOI":"10.1111\/j.1460-9592.2011.03631.x","article-title":"Toxicity of local anesthetic drugs: a pediatric perspective","volume":"22","author":"Lonnqvist","year":"2012","journal-title":"Pediatr Anesth"},{"key":"ref3","doi-asserted-by":"publisher","first-page":"817","DOI":"10.1111\/j.1399-6576.2012.02651.x","article-title":"Bayesian enhanced meta-analysis of postoperative analgesic effiffifficacy of additives for caudal analgesia in children","volume":"56","author":"Engelman","year":"2012","journal-title":"Acta Anaesthesiol Scand"},{"key":"ref4","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1097\/AAP.0000000000000702","article-title":"The European society of regional anaesthesia and pain therapy\/American society of regional anesthesia and pain medicine recommendations on local anesthetics and adjuvants dosage in pediatric regional anesthesia","volume":"43","author":"Suresh","year":"2018","journal-title":"Reg Anesth Pain Med"},{"key":"ref5","doi-asserted-by":"publisher","first-page":"2008","DOI":"10.1213\/ANE.0000000000002014","article-title":"Perineural dexmedetomidine is more effective than clonidine when added to local anesthetic for supraclavicular brachial plexus block: a systematic review and meta-analysis","volume":"124","author":"el-Boghdadly","year":"2017","journal-title":"Anesth Analg"},{"key":"ref6","doi-asserted-by":"publisher","first-page":"149","DOI":"10.4103\/0970-9185.74900","article-title":"A comparative study between clonidine and dexmedetomidine used as adjuncts to ropivacaine for caudal analgesia in paediatric patients","volume":"26","author":"Neogi","year":"2010","journal-title":"J Anaesthesiol Clin Pharmacol"},{"key":"ref7","doi-asserted-by":"publisher","first-page":"1125","DOI":"10.1097\/00000542-199212000-00013","article-title":"Effects of intravenous dexmedetomidine in humans. 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