Infusão contínua de xilazina ou dexmedetomidina em cadelas pré-tratadas ou não com atropina: alterações eletrocardiográficas.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

Alpha-adrenergic agonist drugs were synthesized at the beginning of the sixties. These drugs cause analgesic, sedative, ansiolitic and simpatholitics effects. Their use is extensive in veterinary due to their sedative, analgesic and miorrelaxantes effects. Alpha-adrenergic agonists cause significant changes in the cardiopulmonary system. Bradicardy, arrhythmia, first and second degree atrioventricular obstruction, plus severe respiratory depression, are known as the most common alterations within this group of drugs. These changes were observed on electrocardiogram (ECG). The aim of this study was to compare the eletrocardiographycs changes during xylazine and dexmedetomidine continuous infusion in bitches under or not atropine medication. Twenty healthy mixed-breed bitches, 1 to 7 years old and weighing from 5,5 to 21,76 kilos were split in four groups and randomly assigned to receive during a 30 minutes continuous infusion the following: xylazine (1 mg/kg) G1, xylazine (1mg/kg) associated with atropine (0,044mg/kg) G2, dexmedetomidine (3 μg.kg-1 ) G 3, and dexmedetomidine (3 μg.kg-1 ) plus (0,044mg/kg) G4 atropine. The studiedvariations were: The cardiac frequency, P wave duration and amplitude, PR interval, QRS complex duration, R wave amplitude, and the QT interval of time which were observed by computadorized electrocardiography monitoring. Such variations, were analyzed during the pre-anesthetic examination (MB), at the beginning of the continuous infusion (MO) and at 5 minutes intervals during the 30-minute infusion: M5, M10, M15, M20, M25 e M30. Increase in the PR and QT segment was observed on G1 and G3 groups after alpha-adrenergic agonist drugs. HR, PR interval, QT segment were normal on G2 and G4 groups due to the atropine effect. There were no significant changes in P wave amplitude, QRS complex time and R wave amplitude when all groups were confronted. According to the results of this study, we come to the conclusion that xylazine and dexmedetomidine, change eletrocardiographics parameters in bitches submitted to continuous infusion and dose-dependent. There were few eletrocardiographics changes in dexmedetomidine continuous infusion in animals pre-treatedwith atropine, proving that this pre-medication protocol is a good treatment alternative for dogs.

ASSUNTO(S)

anestesia xilazina dexmedetomidina cão eletrocardiografia medicina veterinaria anesthesia dog alpha-2-adrenergic agonists electrocardiography

ACESSO AO ARTIGO

Documentos Relacionados