Abstract The aim of this study was to evaluate the latency, extent of analgesia, and duration of motor block of levobupivacaine alone and combined with methadone or dexmedetomidine after epidural administration during and after mastectomy in dogs. Twenty-four mature, mixed-breed female dogs were randomly divided into three experimental groups with eight animals each, according to the agents used in lumbosacral epidural analgesia: levobupivacaine 0.75% alone (1.5mg/kg - control group), levobupivacaine 0.75% (1.5 mg/kg) + methadone 1% (0.3 mg/kg), or levobupivacaine 0.75% (1.5 mg/kg) + dexmedetomidine 0.05% (3 µg/kg). During surgery, cardiorespiratory parameters were evaluated. Rescue analgesia was given when there were signs of nociception and was necessary in all three treatment groups. Since all animals received rescue analgesia during the surgery and immediately post-surgery, the duration of the sensitive block were not evaluated. The extent of sensory block was between the 12º and 13º thoracic vertebrae for the control group, 7º thoracic vertebra to 5º lumbar vertebra (methadone group), and 8º thoracic vertebra to 4º lumbar vertebra for the dexmedetomidine group. Methadone or dexmedetomidine combined with levobupivacaine increased the extent of the sensory block and the duration of the motor block in bitches when administered via the epidural route.

Resumo: O objetivo do presente estudo foi avaliar os efeitos cardiorrespiratórios e a recuperação anestésica de onças-pardas (Puma concolor) submetidas à anestesia com detomidina/cetamina e isofluorano ou sevofluorano para avaliação ultrassonográfica abdominal. Para isso, foram utilizados 14 animais divididos aleatoriamente em dois grupos experimentais GISO (n=7) e GSEVO (n=7). Foram submetidos à contenção química com detomidina 0,15mg/kg associada à cetamina 5mg/kg pela via intramuscular, induzidos com propofol 2mg/kg pela via intravenosa e mantidos com isofluorano (GISO) ou sevofluorano. Foram avaliados os parâmetros: frequência cardíaca e respiratória, pressão arterial sistólica, média e diastólica saturação de oxihemoglobina, temperatura retal, pressão venosa central e fração expirada de dióxido de carbono. O tempo para adoção de decúbito esternal e posição quadrupedal também foram avaliados. Não houve diferença estatística para as variáveis cardiorrespiratórias e no tempo para adoção da posição quadrupedal. O tempo para adoção de decúbito esternal foi significativamente menor no GSEVO em relação ao GISO. Concluiu-se que a anestesia de onças pardas com detomidina/cetamina e isoflurano ou sevoflurano foi realizada de maneira segura, com estabilidade cardiorrespiratória e com aumento no tempo para adoção de decúbito esternal no GISO.

Abstract: The aim of this study was to assess the cardiopulmonary effects, the onset time after the administration of a detomidine/ketamine combination, and the recovery from anesthesia of cougars (Puma concolor) anesthetized with detomidine/ketamine and isoflurane or sevoflurane for abdominal ultrasound imaging. Fourteen animals were randomly allocated into two experimental groups: GISO (n=7) and GSEVO (n=7). Chemical restraint was performed using 0.15mg/kg detomidine combined with 5mg/kg ketamine intramuscularly; anesthesia induction was achieved using 2mg/kg propofol intravenously and maintenance with isoflurane (GISO) or sevoflurane (GSEVO). The following parameters were assessed: heart rate, respiratory rate, systolic and diastolic arterial blood pressure, mean arterial blood pressure, oxyhemoglobin saturation, rectal temperature, central venous pressure, and end-tidal carbon dioxide. The time to sternal recumbency (TSR) and time to standing position (TSP) were also determined. There was not statistically significant difference for the cardiopulmonary variables or TSP whereas TSR was significantly shorter in GSEVO. The time to onset of anesthesia was 11.1±1.2 minutes and 11.3±1.8 minutes for GISO and GSEVO, respectively. The anesthesia of cougars with detomidine/ketamine and isoflurane or sevoflurane was conducted with safety, cardiopulmonary stability, and increased time to sternal recumbency in the GISO group.

The challenge of the present work concerned the development and validation of high performance liquid chromatography (HPLC) and UV-Vis spectrophotometric methods for quantitation of methotrexate (MTX) loaded on biodegradable microparticles, composed of copolymers with different solubilities such as chitosan and poly (lactic-co-glycolic acid) (PLGA). The linearity of the analytical curves for MTX were > 0.999 (r2) and the limits of detection (LOD) were 0.014 µg mL-1 and 0.060 µg mL-1 for HPLC and UV-Vis spectrophotometric method, respectively. In addition, both methods were specific, robust, and accurate with a recovery between 89.5% and 105.5%. The method showed precision with relative standard deviations lower than 3.39% for HPLC and 2.90% for UV-Vis spectrophotometry. Statistical analysis revealed that both methods provide equivalent results, and also can be used for quality control of MTX-loaded in drug delivery systems.