Incidência e tratamento da hipotensão após anestesia epidural em cães

• Autor(a) principal: Mortate, Louise Pereira
• Data de Publicação: 2015
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/9604
• topic: Efedrina; Hidroxietilamido; Ringer lactato; Decúbito dorsal; Hematócrito; Ephedrine; Hydroxyethyl starch; Ringer lactate; Dorsal decubitus; Hematocrit; MEDICINA VETERINARIA::PATOLOGIA ANIMAL

Epidural anesthesia is a safe technique when performed correctly. However, complications like hypotension are common and can be intensified by dorsal recumbence since the caudal vena cava is compressed. This study intended to determine the incidence and intensity of arterial hypotension after epidural anesthesia with lidocaine and morphine, as well as identify whether the change to dorsal recumbence may potentiate the hypotensive effect of epidural anesthesia. The efficacy of the treatment with Ringer lactate, 6% hydroxyethyl starch 130/04 or ephedrine was also compared. Forty-five dogs undergoing ovariohysterectomy, orchiectomy or lumpectomy were included in the study. The animals were premedicated with acepromazine (0.03 mg/kg) and pethidine (3 mg/kg, IM) and the anesthesia was induced with midazolam (0.1 mg/kg) and propofol, IV. Superficial plane of anesthesia was maintained with isoflurane and after 15 minutes the dogs received epidural anesthesia with 1% morphine (0.1 mg/kg) and 2% lidocaine without vasoconstrictor to a final volume of 1 mL/4.5 kg. Heart rate (FC), systolic blood pressure (PAS), respiratory rate (f), peripheral oxyhemoglobin saturation (SPO2), end-tidal CO2 (ETCO2), and body temperature (CT) were evaluated. In a pilot study, 12 animals were used to verify the occurrence of hypotension and to adjust the experimental protocol (CG, n = 12). The animals with hypotension were treated with Ringer lactate (GRL, n = 10), 20 mL/kg, administered in 15 minutes; hydroxyethyl starch 130/04 6% (GHA, n = 11), 7 mL/kg, administered in 15 minutes; or ephedrine (GEF n = 12), 0.07 mg/kg, administered as a IV bolus. After 15 minutes of epidural anesthesia, patients were positioned in dorsal recumbence and the PAS was measured during 15 minutes. It was considered hypotension when SBP < 80 mmHg or decreased > 20% from basal value (baseline). The overall incidence of hypotension induced by epidural anesthesia was 31.11% (14/45) and by the dorsal recumbence was 28.88% (13/45). None of the animals that were hypotensive after epidural anesthesia (4/10 in GRL, 4/11 in GHA and 6/12 in GEF) responded to the treatment in GRL, three responded in the GHA, and six responded in the GEF (6/12). It was concluded that hypotension after epidural anesthesia in dogs is frequent, and can be enhanced by changing the position to dorsal recumbence, Hydroxyethyl starch 130/04 and ephedrine were more effective in the treatment of this complication.