Anestesia por infusão contínua de etomidato e etomidato associado ao remifentanil em gatas premedicadas com acepromazina

• Autor(a) principal: Favarato, Lukiya Silva Campos
• Data de Publicação: 2009
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/1434
• topic: Infusão contínua; Etomidato; Hemólise; Rumifentanil; Continuous infusion; Etomidate; Hemolysis; Remifentanil; CNPQ::CIENCIAS AGRARIAS::MEDICINA VETERINARIA::CLINICA E CIRURGIA ANIMAL::ANESTESIOLOGIA ANIMAL

The imidazole derivative etomidate is classified as a non-barbituric general anesthetic with hypnotic action for intravenous usage. Remifentanil is a selective μ- receptor agonist opioid of ultra-short action and high analgesic potency with an unique pharmacokinetic due to a lateral metil-ester branch that allows a fast metabolism by non-specific esterases (carboxylesterases) present in blood and tissues. Twenty female mongrel cats were used, all healthy, with a mean weight of 3.5±0.49 kg, admitted for an elective overiohysterectomy. Pre-anesthetic medication was made with acepromazine, 0.1mg.Kg-1 intravenously, and etomidate was used for anesthetic induction, also intravenously, on a dose of 3 mg.kg-1. Continuous act, animals were randomly divided in 2 groups of 10 animals each, maintaining anesthesia for 45 minutes using the protocols: for group 1 (IE), continuous infusion of etomidate at a rate of 0.4 mg.kg- 1.min-1; for group 2 (IER), continuous infusion of etomidate and remifentanil at rates of 0.3 mg.kg-1.min-1 and 0.4 μg.kg-1.min-1, respectively. The following parameters where analyzed: heart rate; oxyhemoglobin saturation; systolic arterial pressure; respiratory rate; body temperature; arterial blood gas; sodium, potassium, ionized calcium, chloride and glucose dosages; autonomic responses to nociceptive stimulus; electrocardiogram; palpebral, corneal, laryngeal and tracheal reflexes; time needed for recovery from the anesthesia; adverse effects record; final solution osmolarity; total number of erythrocytes; hematocrit; hemoglobin measure; total, direct and indirect bilirrubin; plasma free hemoglobin; haptoglobin and; erythrocyte fragility. Scheduled times for measurements were T0 (before), before pre-anesthetic administration (MPA); T1 (MPA), 20 minutes after MPA; T2 (5 min), 5 minutes after anesthetic induction and orotracheal intubation; T3 (15 min), T4 (30min), T5 (45min) and T6 (3h 45min) at 15, 30, 45 and 3 hours and 45 minutes after T2, respectively. Continuous infusion of etomidate and its association with remifentanil in cats promoted heart rate and blood pressure stability, hypoventilation and respiratory acidosis. Etomidate in continuous infusion could not suppress autonomic responses to nociceptive stimulus and so, inadequate for surgery procedures. Etomidate associated to remifentanil efficiently controlled autonomic responses to nociceptive stimulus before and after surgery. Both the infusions tested promoted transitory hyperglycemia during anesthesia and after it. Etomidate associated or not with remifentanil by continuous infusion promoted a longer recovery with intense side effects such as myoclonus and emesis. Etomidate and etomidate associated with remifentanil infusions, associated with acepromazine promoted important decrease in erythrocytes number, hematocrit and hemoglobin. Both the infusions tested promoted increases in free hemoglobin and bilirrubin and decrease of haptaglobin as a result of intravascular hemolysis. Etomidate alone and its association with remifentanil in intravascular infusion did not promote any clinical signs of icterus or erythrocyte fragility.