title: Effects of the opioid remifentanil on the arrhythmogenicity of epinephrine in halothane-anesthetized dogs.
abstract: Opioids may exert a protective effect against ventricular arrhythmias via a vagally mediated mechanism. This study evaluated the effects of the opioid remifentanil on arrhythmogenicity of epinephrine during halothane anesthesia. Eight dogs were assigned to 2 treatments in a randomized crossover design, with 1-week intervals between treatments. Anesthesia was maintained with 1.3% end-tidal halothane in oxygen and mechanical ventilation to maintain eucapnia. A constant rate infusion of remifentanil (0.72 microg/kg/min) was administered throughout the study in the experimental treatment, while control animals received physiologic saline as placebo. The arrhythmogenic dose of epinephrine (ADE), defined as 4 premature ventricular complexes (PVCs) within 15 s, was determined by administering progressively increasing infusion rates of epinephrine (2.5, 5.0, and 10 microg/kg/min), allowing 20 min intervals between each infusion rate. In both treatments, epinephrine infusions induced bradyarrhythmias and atrioventricular conduction disturbances, which were followed by escape beats and PVCs. In the remifentanil treatment, mean +/- s ADE values (11.3 +/- 4.9 microg/kg) did not differ from values observed in control animals (9.9 +/- 6.1 microg/kg). On the basis of the ADE model for assessing the arrhythmogenity of drugs during halothane anesthesia, the present study did not demonstrate a protective effect of remifentanil (0.72 microg/kg/min) against ventricular arrhythmias in dogs.
authors.affiliation: Department of Veterinary Surgery and Anesthesiology, Faculdade de Medicina Veterinária e Zootecnia, Universidade Estadual Paulista, Botucatu, São Paulo, CEP 18618-000, Brazil.
authors.forename: Natache A
authors.initials: NA
authors.lastname: Garofalo
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Teixeira-Neto
authors.forename: Denise S
authors.initials: DS
authors.lastname: Schwartz
authors.forename: Maria do Carmo F
authors.initials: Mdo C
authors.lastname: Vailati
authors.forename: Paulo V M
authors.initials: PV
authors.lastname: Steagall
mesh_terms: D000701:Analgesics, Opioid / Q000494:pharmacology*; D000758:Anesthesia / Q000662:veterinary; D018685:Anesthetics, Inhalation / Q000008:administration & dosage / Q000009:adverse effects*; D000818:Animals; D000889:Anti-Arrhythmia Agents / Q000627:therapeutic use; D001145:Arrhythmias, Cardiac / Q000139:chemically induced / Q000188:drug therapy / Q000662:veterinary*; D018592:Cross-Over Studies; D004283:Dog Diseases / Q000139:chemically induced / Q000188:drug therapy*; D004285:Dogs; D004562:Electrocardiography / Q000662:veterinary; D004837:Epinephrine / Q000008:administration & dosage; D005260:Female; D006221:Halothane / Q000008:administration & dosage / Q000009:adverse effects*; D006339:Heart Rate / Q000187:drug effects; D007263:Infusions, Parenteral / Q000662:veterinary; D010880:Piperidines / Q000494:pharmacology*; D011897:Random Allocation; D000077208:Remifentanil
chemical_list: D000701:Analgesics, Opioid; D018685:Anesthetics, Inhalation; D000889:Anti-Arrhythmia Agents; D010880:Piperidines; D000077208:Remifentanil; D006221:Halothane; D004837:Epinephrine
references.citation: Am J Physiol. 1976 Jun;230(6):1469-73
references.pmid: 59552
references.citation: Lab Anim Sci. 1987 Oct;37(5):587-95
references.pmid: 3320515
references.citation: Anesthesiology. 1971 Jul;35(1):48-53
references.pmid: 4397352
references.citation: Am Heart J. 1988 Mar;115(3):598-605
references.pmid: 3278576
references.citation: J Am Vet Med Assoc. 1994 Dec 15;205(12):1679-84
references.pmid: 7744639
references.citation: Cardiovasc Res. 1978 Mar;12(3):167-72
references.pmid: 647721
references.citation: Can J Vet Res. 1997 Jul;61(3):221-6
references.pmid: 9243003
references.citation: Am J Vet Res. 1993 Dec;54(12):2139-44
references.pmid: 7906930
references.citation: Can J Vet Res. 1997 Oct;61(4):241-5
references.pmid: 9342445
references.citation: J Pharmacol Exp Ther. 1997 Apr;281(1):226-32
references.pmid: 9103501
references.citation: Am Heart J. 1978 Feb;95(2):197-203
references.pmid: 74946
references.citation: Anesthesiology. 1996 Apr;84(4):865-72
references.pmid: 8638841
references.citation: Vet Surg. 1994 Jan-Feb;23(1):61-6
references.pmid: 8140741
references.citation: Can J Vet Res. 2001 Apr;65(2):116-24
references.pmid: 11346256
references.citation: Anesth Analg. 1983 Feb;62(2):129-34
references.pmid: 6829912
references.citation: Can J Physiol Pharmacol. 1989 Jul;67(7):801-9
references.pmid: 2766111
references.citation: Clin Exp Pharmacol Physiol. 1993 Feb;20(2):95-102
references.pmid: 8383026
references.citation: Am J Vet Res. 1993 Dec;54(12):2132-8
references.pmid: 7906929
references.citation: Anesth Analg. 1999 Oct;89(4 Suppl):7
references.pmid: 10511072
references.citation: Anesthesiology. 1970 Aug;33(2):193-213
references.pmid: 4916273
references.citation: Can J Vet Res. 1994 Oct;58(4):248-53
references.pmid: 7889455