Patients will be randomly allocated to receive either a saline placebo or lidocaine continuous infusions during surgery. Morphinic consumption will be assessed from the end of the procedure until the third day after surgery. Secondary criteria will concern post-operative recovery, pain and postoperative nausea and vomiting, other medical and surgical complications, and toxicity. Plasma lidocaine concentrations will be measured in patients who had received lidocaine in order to determine the safety and efficiency of our infusion protocol.