Pulmonary complications remain the most frequent of postoperative complications (32-60), especially after upper abdominal surgery (14-41). Chronic respiratory insufficiency (80) also continues to be a major risk factor, in spite of the progress made in both anesthesiology and postoperative care. In the immediate postoperative period, weaning from mechanical ventilation is one of the most dangerous phases of anesthesia (84). We discuss the importance of weaning procedures, in particular, in patients with a high risk of pulmonary complications.