Intravenous Dexmedetomidine as an Adjuvant to Locoregional Anesthesia in Pediatric Surgery

The main objective of this study is to study the impact of intravenous dexmedetomidine combined with locoregional anesthesia on postoperative pain in children undergoing surgery. Secondary objectives was to compare beetwen groups : Post-operative pain; opioid consumption; incidence of emergence delirium, post-operative behavioral disorders, length of stay in the PACU, adverse events , parental satisfaction and quality of life.The goal of this clinical trial is to assess intravenous dexmedetomidine to prevent post-operative pain in children undergoing surgery. This study is prospective and children will be randomized in one of the following arm: * Dexmedetomidine (experimental treatment) * Placebo The experimental treatment or placebo will be administrated at one time point at the time of incision. Participants and their legal representative will have to respond to questionnaires at several time points following the surgery: Day 1, Week 1, Month 3 and Month 6.