Twenty patients with major abdominal hernia were treated by prosthesis interposed in pre or intraperitoneal position by medial incision. This surgery can produce healthy respiratory morbidity. Indeed, these patients are commonly obeses and smokers. The reintegration of the viscera in the abdominal cavity increases the pressure in this cavity and pertubs the diaphragmatic motility. The association of peridural technique and propofol perfusion gives an excellent awakening combined to a good postoperative analgesia. So this association permits to obtain from patient a helpful collaboration which limits dramatically the postoperative complications.