Cardiopulmonary effects and eyeball centralization with low-dose atracurium in spontaneously breathing, anesthetized dogs/Avaliacao cardiopulmonar e da centralizacao do globo ocular em caes com baixas doses de atracurio mantidos em anestesia inalatoria sob ventilacao espontanea

• Published in: Ciência rural Vol. 40; no. 7; pp. 1576 - 1582
• Main Authors: Carregaro, Adriano Bonfim, Freitas, Gabrielle Coelho, da Cruz, Fernando Silverio Ferreira, Machado, Melissa, Tognoli, Guilherme Kanciukaitis, Pipp, Ney Luis
• Format: Journal Article
• Language: English; Spanish
• Published: Universidade Federal de Santa Maria 01-07-2010
• Subjects: atracurium; atracúrio; Carbonates; corneal ulcer; cão; dog; Dosage and administration; Heart beat; Hemoglobin; Neuromuscular blocking agents; spontaneous breathing; ventilação espontânea; úlcera corneana
• ISSN: 0103-8478; 1678-4596

The objective was to determine the cardiopulmonary effects and eyeball centralization time obtained with 15 or 30µg [kg.sup.-1] of atracurium in anesthetized dogs under spontaneous breathing. Eighteen healthy adult mixed-breed dogs were used, which received 0.1mg [kg.sup.-1] acepromazine and 0.5mg [kg.sup.-1] morphine IM, followed by 4mg [kg.sup.-1] propofol IV and maintained on isoflurane anesthesia with spontaneous breathing. Animals received 1mL 0.9% NaCl IV (CG), 15µg [kg.sup.-1] (G15) or 30µg [kg.sup.-1] (G30) of atracurium IV Eyeball centralization time was measured; heart rate (HR), systolic (SAP), mean (MAP) and diastolic (DAP) arterial pressures, respiratory rate (RR), tidal volume (Vt) and minute volume (Vm) were determined every 5min, and pH, arterial C[O.sub.2] pressure (PaC[O.sub.2]), arterial [O.sub.2] pressure (Pa[O.sub.2]), hemoglobin oxygen saturation (Sa[O.sub.2]) bicarbonate (HC[O.sup.-.sub.3] and base excess (BE) every 15min until 60min. Both doses of atracurium produced a similar period of eyeball centralization. Vt in groups treated with atracurium was lower than in CG up to 15min. Vm in G15 differed from CG up to 10min and in G30 up to 25min. No differences were observed for cardiovascular parameters, RR, Sa[O.sub.2], Pa[O.sub.2], HC[O.sup.-.sub.3] and BE. pH decreased in CG between 30 and 60min and in G15 and G30 at 15min. G30 differed from CG between 15 and 30min. PaC[O.sub.2] in GC differed from baseline between 30 and 60min and in G15 differed at 15min. Atracurium at the dose of 15µg [kg.sup.-1] is adequate for short corneal procedures in inhalant-anesthetized dogs under spontaneous breathing. Key words: dog, atracurium, spontaneous breathing, corneal ulcer. Objetivou-se determinar os efeitos cardiopulmonares e o tempo de centralizacao do globo ocular obtidos com 15 ou 30µg [kg.sup.-1] de atracurio em caes anestesiados sob ventilacao espontanea. Dezoito caes adultos foram pre-medicados com 0,1mg [kg.sup.-1] de acepromazina e 0,5mg [kg.sup.-1] de morfina IM, anestesiados com 4mg [kg.sup.-1] de propofol IV e mantidos sob anestesia inalatoria com isofluorano em ventilacao espontanea. Os animais receberam 1mL de NaCl 0,9% IV (GC), 15µg [kg.sup.-1] (G15) ou 30µg [kg.sup.-1] de atracurio IV Mensuraram-se o tempo de centralizacao do globo ocular, a frequencia cardiaca (FC), as pressoes arteriais sistolica (PAS), media (PAM) e diastolica (PAD), a frequencia respiratoria (f), o volume corrente (Vt) e o volume minuto (Vm) a cada 5min, e o pH, as pressoes arteriais de C[O.sub.2] (PaC[O.sub.2]) e [O.sub.2] (Pa[O.sub.2]), a saturacao de oxigenio nas hemoglobinas (Sa[O.sub.2]) o bicarbonato (HC[O.sup.-.sub.3]) e o excesso de base (BE) a cada 15min, ate 60min. Ambas as doses de atracurio produziram similar periodo de centralizacao. Os grupos tratados com atracurio apresentaram menores valores para Vt ate 15min. O Vm, no G15, diferiu do GC ate 10min e do G30 ate 25min. Nao foram observadas alteracoes nos parametros cardiovasculares f, Sa[O.sub.2], Pa[O.sub.2], HC[O.sup.-.sub.3] e EB. O pH diminuiu no GC entre 30 e 60min e em G15 e G30 aos 15min. A PaC[O.sub.2] elevou'se no GC entre 30 e 60min e no G15 aos 15min. A dose de 15µg [kg.sup.-1] de atracurio demonstrou ser adequada para centralizacao do globo ocular, podendo ser utilizada em procedimentos corneanos de curta duracao em caes anestesiados com isoflurano e mantidos sob ventilacao espontanea. Palavras-chave: cao, atracurio, ventilacao espontanea, ulcera corneana.