Avalia??o morfol?gica, eletromiogr?fica e por termografia infravermelha do bloqueio do plexo braquial em coelhos guiado por ultrassonografia

• Autor(a) principal: Moreira, Rodrigo Mencalha
• Data de Publicação: 2016
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFRRJ
• Texto Completo: https://tede.ufrrj.br/jspui/handle/jspui/1473
• topic: Brachial plexus; Ultrasonography; Plexo braquial; Ultrassonografia; Termografia; Termography; Medicina Veterin?ria

The brachial plexus block (BPB) remains one of the most intriguing topics of contemporary anesthesia because, due to the complex organization of this structure is associated with a significant number of failures. The aim of this study was to evaluate the effectiveness of ultrasound-guided associated with peripheral nerve stimulation BPB in rabbits. Initially, 80 plexus were dissected, so as to enable researchers in the gross anatomy of the region. Later, in the in vivo study, we used 40 male rabbits which were randomly divided into two groups: Group 1: Ultrasound-guided associated with peripheral nerve stimulation (US/ENP) BPB; Group 2: Peripheral nerve stimulation-guided (ENP) BPB. Under general anesthesia, axillary BPB was performed, under lidocaine 2% without vasoconstrictor injection at the maximum dose of 0,7ml.kg-1. The motor latency, motor block and volume difference between the BPB between the techniques were evaluated by recording motor action potentials compounds of the radial nerve. The measurement of skin temperature (ST), by infrared thermography, was carried out in areas of interest, previously stipulated in the forepaw, digits and forearm, in order to verify the correlation of the variation in the effectiveness of BPB. In 92.5% of the animals the nerves resulting consisted of connections between the ventral rami of the last four cervical spinal nerves (C5, C6, C7, C8) and first thoracic (T1). No significant difference was observed in time performance of US/ENP-guided BPB (4.3 ? 0.73 min) or ENP-guided BPB (6.4 ? 0.68 minutes), however, significantly less volume administration was necessary to local anesthetic in the US/ENP-guided BPB (0.61 ? 0.15 mL vs 1.22 ? 0.17; P <0.0001). Despite the lower volume used, it was observed that the US/ENP group had shorter on set time block (1.1 ? 0.45) compared to ENP group (1.95 ? 0.79; P <0.01). The US/ENP-guided BPB or ENP-guided BPB resulted in a substantial and significant increase in ST areas of interest in the radial, musculocutaneous, median and ulnar nerves (P < 0.001), however this increase was outstanding in hand and digits regions Thus it is concluded that the US/ENP-guided BPB is an effective and easy technique to reproduce in this experimental model which required lower volume of local anesthetic, provided a smaller motor latency and a higher motor blockade time when compared to the ENP-guided BPB. The increase in ST is a highly effective tool for assessing the effectiveness of BPB with predictive value, sensitivity and specificity of 100%. Furthermore, future clinical studies are needed to verify its correlation with the anaesthetized area.