Comparison Between Levobupivacaine and Levobupivacaine With Dexmedetomidine in Ultrasound Guided Pectoral Nerve Block

A double blind prospective randomized controlled trial in which the effect of single shot levobupivacaine 0,25% will be compared with the effect of levobupivacaine 0.25% in association with dexmedetomidine when performing an ultrasound guided modified pectoral nerve block , in patients undergoing a mastectomy with axillar procedure. The difference in effect will be evaluated by monitoring the postoperative morphine consumption in both groups . The hypothesis is that there is a significant decrease in morphine consumption during the first 24h postoperatively due to association of dexmedetomidine to the local anesthetic compared to the local anesthetic alone when performing a ultrasound guided modified pectoral nerve block. The morphine consumption will be the primary outcome parameter.