Before anesthesia induction, these patients receive an intravenous lidocaine infusion (bolus 1,5 mg.kg-1 followed by a continuous infusion of 2mg.kg-1.h during 24 hours) or an equal volume of placebo. Then the anesthesia is induced with propofol, sufentanil et rocuronium. The postoperative analgesia is provided by paracetamol, tramadol and patient-controlled analgesia (PCA) with morphine or oral oxycodone. A polysomnography is registred on the preoperative night and on the first postoperative night.