{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,7,30]],"date-time":"2025-07-30T16:36:33Z","timestamp":1753893393303,"version":"3.41.2"},"reference-count":35,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2025,6,3]],"date-time":"2025-06-03T00:00:00Z","timestamp":1748908800000},"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. Vet. Sci."],"abstract":"<jats:sec><jats:title>Introduction<\/jats:title><jats:p>Partial intravenous anesthesia can be used to reduce the adverse effects of inhalant anesthetics, and opioids are often used in this context in dogs and cats. The opioid butorphanol was recently shown to dose-dependently reduce the minimum alveolar concentration of isoflurane in cats. The aim of this study was to characterize the hemodynamic effects of butorphanol in isoflurane-anesthetized cats.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>Six cats were anesthetized with isoflurane and administered butorphanol to maintain target plasma concentrations (TPCs) of 0, 1.1, 2.2 and 4.4\u202f\u03bcg\u202fmL<jats:sup>\u22121<\/jats:sup>, with or without concurrent administration of atropine. The isoflurane concentration was adjusted to maintain equipotency based on the results of a previous study. Cardiorespiratory variables were measured at each plasma butorphanol concentration.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>Severe bradycardia and hypotension were observed in one cat at the 4.4\u202f\u03bcg\u202fmL<jats:sup>\u22121<\/jats:sup> TPC and in one cat at the 2.2\u202f\u03bcg\u202fmL<jats:sup>\u22121<\/jats:sup> TPC without atropine. Treatments without atropine and the 4.4\u202f\u03bcg\u202fmL<jats:sup>\u22121<\/jats:sup> TPC were not studied in subsequent cats. Butorphanol significantly reduced heart rate, cardiac index and oxygen delivery index, and increased systemic vascular resistance index and oxygen consumption index in a plasma concentration-dependent manner.<\/jats:p><\/jats:sec><jats:sec><jats:title>Discussion<\/jats:title><jats:p>In isoflurane-anesthetized cats, at the TPCs studied, butorphanol caused more cardiovascular depression than a higher, equipotent concentration of isoflurane alone.<\/jats:p><\/jats:sec>","DOI":"10.3389\/fvets.2025.1600753","type":"journal-article","created":{"date-parts":[[2025,6,3]],"date-time":"2025-06-03T05:21:45Z","timestamp":1748928105000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Target-controlled infusions of butorphanol worsen hemodynamics in isoflurane-anesthetized cats"],"prefix":"10.3389","volume":"12","author":[{"given":"Bruno H.","family":"Pypendop","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alessia","family":"Cenani","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Marcela L.","family":"Machado","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Linda S.","family":"Barter","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2025,6,3]]},"reference":[{"key":"ref1","first-page":"276","article-title":"Partial intravenous anesthesia in cats and dogs","volume":"54","author":"Duke","year":"2013","journal-title":"Can Vet J"},{"key":"ref2","doi-asserted-by":"publisher","first-page":"1065","DOI":"10.2460\/ajvr.70.9.1065","article-title":"Effects of remifentanil on measures of anesthetic immobility and analgesia in cats","volume":"70","author":"Brosnan","year":"2009","journal-title":"Am J Vet Res"},{"key":"ref3","doi-asserted-by":"publisher","first-page":"533","DOI":"10.1111\/jvp.12886","article-title":"Phenylpiperidine opioid effects on isoflurane minimum alveolar concentration in cats","volume":"43","author":"Brosnan","year":"2020","journal-title":"J Vet Pharmacol Ther"},{"key":"ref4","doi-asserted-by":"publisher","first-page":"1274","DOI":"10.2460\/ajvr.1997.58.11.1274","article-title":"Effect of alfentanil on the minimum alveolar concentration of isoflurane in cats","volume":"58","author":"Ilkiw","year":"1997","journal-title":"Am J Vet Res"},{"key":"ref5","doi-asserted-by":"publisher","first-page":"1198","DOI":"10.2460\/ajvr.2002.63.1198","article-title":"Effects of morphine, butorphanol, buprenorphine, and U50488h on the minimum alveolar concentration of isoflurane in cats","volume":"63","author":"Ilkiw","year":"2002","journal-title":"Am J Vet Res"},{"key":"ref6","doi-asserted-by":"publisher","first-page":"581","DOI":"10.2460\/ajvr.70.5.581","article-title":"Effect of remifentanil hydrochloride administered via constant rate infusion on the minimum alveolar concentration of isoflurane in cats","volume":"70","author":"Ferreira","year":"2009","journal-title":"Am J Vet Res"},{"key":"ref7","doi-asserted-by":"publisher","first-page":"518","DOI":"10.1097\/00000542-198710000-00013","article-title":"The enflurane sparing effect of sufentanil in dogs","volume":"67","author":"Hall","year":"1987","journal-title":"Anesthesiology"},{"key":"ref8","doi-asserted-by":"publisher","first-page":"150","DOI":"10.2460\/ajvr.71.2.150","article-title":"Effects of remifentanil on the minimum alveolar concentration of isoflurane in dogs","volume":"71","author":"Monteiro","year":"2010","journal-title":"Am J Vet Res"},{"key":"ref9","doi-asserted-by":"publisher","first-page":"325","DOI":"10.1016\/0376-8716(85)90065-1","article-title":"Butorphanol","volume":"14","author":"Pachter","year":"1985","journal-title":"Drug Alcohol Depend"},{"key":"ref10","doi-asserted-by":"publisher","first-page":"165","DOI":"10.1016\/j.vaa.2021.12.004","article-title":"Effect of intravenous butorphanol infusion on the minimum alveolar concentration of isoflurane in cats","volume":"49","author":"Pypendop","year":"2022","journal-title":"Vet Anaesth Analg"},{"key":"ref11","doi-asserted-by":"publisher","first-page":"414","DOI":"10.1111\/j.1532-950x.1992.tb01719.x","article-title":"Cardiovascular and pulmonary effects of atropine reversal of oxymorphone-induced bradycardia in dogs","volume":"21","author":"Copland","year":"1992","journal-title":"Vet Surg"},{"key":"ref12","doi-asserted-by":"publisher","first-page":"52","DOI":"10.1111\/vaa.12397","article-title":"Cardiovascular effects of dexmedetomidine, with or without Mk-467, following intravenous administration in cats","volume":"44","author":"Pypendop","year":"2017","journal-title":"Vet Anaesth Analg"},{"key":"ref13","doi-asserted-by":"publisher","first-page":"21","DOI":"10.1111\/j.1365-2885.2012.01385.x","article-title":"Pharmacokinetics and pharmacodynamics of butorphanol following intravenous administration to the horse","volume":"36","author":"Knych","year":"2013","journal-title":"J Vet Pharmacol Ther"},{"key":"ref14","doi-asserted-by":"publisher","first-page":"883","DOI":"10.1111\/jvp.13014","article-title":"Pharmacokinetics of butorphanol in male neutered cats anesthetized with isoflurane","volume":"44","author":"Pypendop","year":"2021","journal-title":"J Vet Pharmacol Ther"},{"key":"ref15","doi-asserted-by":"publisher","first-page":"753","DOI":"10.1016\/j.vaa.2019.05.012","article-title":"Cardiopulmonary effects of dexmedetomidine, with and without vatinoxan, in isoflurane-anesthetized cats","volume":"46","author":"Jaeger","year":"2019","journal-title":"Vet Anaesth Analg"},{"key":"ref16","doi-asserted-by":"publisher","first-page":"384","DOI":"10.1097\/00000542-197504000-00003","article-title":"Mac expanded: Ad50 and Ad95 values of common inhalation anesthetics in man","volume":"42","author":"de Jong","year":"1975","journal-title":"Anesthesiology"},{"key":"ref17","doi-asserted-by":"publisher","first-page":"159","DOI":"10.1111\/j.1532-950x.1993.tb01692.x","article-title":"Cardiorespiratory effects of combined midazolam and butorphanol in isoflurane-anesthetized cats","volume":"22","author":"Gross","year":"1993","journal-title":"Vet Surg"},{"key":"ref18","doi-asserted-by":"publisher","first-page":"715","DOI":"10.1213\/00000539-198110000-00003","article-title":"Hemodynamic effects of butorphanol-oxygen anesthesia in dogs","volume":"60","author":"Sederberg","year":"1981","journal-title":"Anesth Analg"},{"key":"ref19","doi-asserted-by":"publisher","first-page":"329","DOI":"10.2460\/ajvr.1983.44.02.329","article-title":"Cardiopulmonary effects of butorphanol tartrate in dogs","volume":"44","author":"Trim","year":"1983","journal-title":"Am J Vet Res"},{"key":"ref20","doi-asserted-by":"crossref","first-page":"355","DOI":"10.1002\/9781119830306.ch23","article-title":"Opioids","volume-title":"Veterinary anesthesia and analgesia","author":"Simon","year":"2024"},{"key":"ref21","first-page":"248","article-title":"The cardiovascular sparing effect of fentanyl and atropine, administered to enflurane anesthetized dogs","volume":"58","author":"Ilkiw","year":"1994","journal-title":"Can J Vet Res"},{"key":"ref22","doi-asserted-by":"publisher","first-page":"26","DOI":"10.1016\/j.vaa.2021.09.001","article-title":"Effect of fentanyl, with or without treatment of bradycardia, on the minimum alveolar concentration of isoflurane and cardiovascular function in dogs","volume":"49","author":"Machado","year":"2022","journal-title":"Vet Anaesth Analg"},{"key":"ref23","doi-asserted-by":"publisher","first-page":"1267","DOI":"10.2460\/ajvr.1997.58.11.1267","article-title":"Cardiovascular effects of equipotent isoflurane and alfentanil\/isoflurane minimum alveolar concentration multiple in cats","volume":"58","author":"Pascoe","year":"1997","journal-title":"Am J Vet Res"},{"key":"ref24","doi-asserted-by":"publisher","first-page":"109","DOI":"10.1254\/jphs.crj05001x","article-title":"Butorphanol: effects of a prototypical agonist-antagonist analgesic on kappa-opioid receptors","volume":"98","author":"Commiskey","year":"2005","journal-title":"J Pharmacol Sci"},{"key":"ref25","doi-asserted-by":"publisher","first-page":"385","DOI":"10.1016\/j.yrtph.2010.12.007","article-title":"Uniform assessment and ranking of opioid \u03bc receptor binding constants for selected opioid drugs","volume":"59","author":"Volpe","year":"2011","journal-title":"Regul Toxicol Pharmacol"},{"key":"ref26","doi-asserted-by":"publisher","first-page":"817","DOI":"10.1016\/j.cvsm.2013.03.012","article-title":"Management of cardiac emergencies in small animals","volume":"43","author":"DeFrancesco","year":"2013","journal-title":"Vet Clin North Am Small Anim Pract"},{"key":"ref27","doi-asserted-by":"publisher","first-page":"398","DOI":"10.1016\/j.tvjl.2012.03.019","article-title":"Cardiorespiratory and neuroendocrine changes induced by methadone in conscious and in isoflurane anaesthetised dogs","volume":"194","author":"Garofalo","year":"2012","journal-title":"Vet J"},{"key":"ref28","doi-asserted-by":"publisher","first-page":"317","DOI":"10.1111\/j.1365-2885.2008.01042.x","article-title":"Comparison of the cardio-respiratory effects of methadone and morphine in conscious dogs","volume":"32","author":"Maiante","year":"2009","journal-title":"J Vet Pharmacol Ther"},{"key":"ref29","doi-asserted-by":"publisher","first-page":"PL45","DOI":"10.1016\/0024-3205(94)00426-s","article-title":"The mu1, mu2, delta, kappa opioid receptor binding profiles of methadone stereoisomers and morphine","volume":"56","author":"Kristensen","year":"1995","journal-title":"Life Sci"},{"key":"ref30","doi-asserted-by":"publisher","first-page":"1276","DOI":"10.2460\/ajvr.1990.51.08.1276","article-title":"Cardiovascular effects of butorphanol in halothane-anesthetized dogs","volume":"51","author":"Greene","year":"1990","journal-title":"Am J Vet Res"},{"key":"ref31","doi-asserted-by":"publisher","first-page":"H316","DOI":"10.1152\/ajpheart.1993.265.1.H316","article-title":"Dependence of cardiac filling pressure on cardiac output during rest and dynamic exercise in dogs","volume":"265","author":"Sheriff","year":"1993","journal-title":"Am J Physiol"},{"key":"ref32","first-page":"184","article-title":"Isoflurane and total oxygen consumption in spontaneously breathing dogs in basal metabolic conditions","volume":"34","author":"Samodelov","year":"1985","journal-title":"Anaesthesist"},{"key":"ref33","doi-asserted-by":"publisher","first-page":"315","DOI":"10.1152\/jappl.1979.46.2.315","article-title":"Influence of cardiac output on intrapulmonary shunt","volume":"46","author":"Lynch","year":"1979","journal-title":"J Appl Physiol"},{"key":"ref34","first-page":"225","article-title":"Comparative gastrointestinal and biliary tract effects of morphine and butorphanol (Stadol)","volume":"10","author":"Roebel","year":"1979","journal-title":"J Med"},{"key":"ref35","doi-asserted-by":"publisher","first-page":"351","DOI":"10.1113\/jphysiol.1979.sp012855","article-title":"Effects of atropine on secretion and motility in isolated gastric mucosa and attached muscularis externa from ferret and cat","volume":"292","author":"Roth","year":"1979","journal-title":"J Physiol"}],"container-title":["Frontiers in Veterinary Science"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fvets.2025.1600753\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,6,3]],"date-time":"2025-06-03T05:21:46Z","timestamp":1748928106000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/fvets.2025.1600753\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,6,3]]},"references-count":35,"alternative-id":["10.3389\/fvets.2025.1600753"],"URL":"https:\/\/doi.org\/10.3389\/fvets.2025.1600753","relation":{},"ISSN":["2297-1769"],"issn-type":[{"type":"electronic","value":"2297-1769"}],"subject":[],"published":{"date-parts":[[2025,6,3]]},"article-number":"1600753"}}