Evaluation of two regional anesthetic methods on the front limb of dogs using hyperbaric bupivacaine

PURPOSE: To evaluate the effects of bupivacaine 0.5 and 0.25% in intravenous regional anesthesia (IVRA) and brachial plexus block (BPB), respectively, on anesthesia, motor block and cardiovascular parameters in dogs. METHODS: Fourteen healthy adult dogs averaging 10 kilograms (kg) of body weight. Animals were randomly assigned to receive one of the two treatments IVRA (n=7) or BPB (n=7). All the animals were sedated with acepromazine (0.1 mg/kg intramuscular). To execute the BPB was used an electrical nerve stimulation. Anesthesia, motor block, sedation, cardiovascular and respiratory effects were measured as effect of the treatment. RESULTS: BPA showed superior efficiency and duration of anesthesia (BPB - 456 ± 94 minutes vs IVRA - 138 ± 44) as well as motor block. There only physiologic parameter which change were the systolic pressure in BPB and respiratory rate for both treatments. CONCLUSION: In dogs the 0.25 % hyperbaric bupivacaine in BPB produces a front limb anesthesia about three times more than the 0.5 % in IVRA, with ptosis of the limb blocked and little interference in the cardiovascular system but with decrease in respiratory rate.