Influência da dexmedetomidina/atropina sobre as alterações da variação de pulso induzidas pela hemorragia seguida por reposição volêmica em cães anestesiados com isoflurano

Detalhes bibliográficos
Ano de defesa: 2014
Autor(a) principal: Diniz, Miriely Steim [UNESP]
Orientador(a): Não Informado pela instituição
Banca de defesa: Não Informado pela instituição
Tipo de documento: Dissertação
Tipo de acesso: Acesso aberto
Idioma: por
Instituição de defesa: Universidade Estadual Paulista (Unesp)
Programa de Pós-Graduação: Não Informado pela instituição
Departamento: Não Informado pela instituição
País: Não Informado pela instituição
Palavras-chave em Português:
Link de acesso: http://hdl.handle.net/11449/113879
Resumo: This study aimed to evaluate the effects of dexmedetomidine on pulse pressure variation (PPV) changes induced by hemorrhage followed by volume replacement (VR) during isoflurane anesthesia. In a prospective, randomized crossover study, 8 adult dogs (19.5 to 29.2 kg) were anesthetized with 1.3 times the minimum alveolar concentration of isoflurane alone or isoflurane/dexmedetomidine (2 μg/kg/h) (2-week washout intervals). Atropine (0.03 mg/kg IM and 0.01 mg/kg IV) was administered 30 minutes prior to hemorrhage in the dexmedetomidine treatment. In both treatments neuromuscular blockade was produced by atracurium (0.3 mg/kg bolus, followed by 0.3 mg/kg/hour) for performing volume controlled ventilation (tidal volume: 12 mL/kg, inspiration to expriation ratio: 1:1.3 and respiratory rate: 16-20 breaths/min) with a positive end-expiratory pressure of 7 cm H2O. After recording baseline data, progressive withdrawal of 10, 20, and 30% of the estimated blood volume (HV10, HV20, and HV30, respectively) was followed by VR with autologous blood in the same proportion (RV10, RV20, and RV30, respectively). In 4/8 isoflurane-anesthetized dogs hemorrhage induced hypotension [mean arterial pressure (MAP) < 60 mmHg]. Based on MAP changes after hemorrhage during isoflurane anesthesia, dogs were divided in hypotensive (HG) and normotensive groups (NG). During isoflurane anesthesia (HG and NG), stroke index and cardiac index were significantly (P < 0.05) decreased from baseline after hemorrhage, while VR normalized or significantly increased these variables. The PPV (%) was increased by hemorrhage [from 7 (9, 5) (baseline) to 20 (27, 12) and 27 (40, 17) at HV20 and HV30, respectively] [mean (upper, lower ranges)] only in isoflurane-anesthetized dogs that became hypotensive; PPV returned to baseline after VR. Dexmedetomidine caused sustained increases in systemic vascular resistance (HG and NG), and prevented the ...