Postoperative hypoxemia complicates between 30 to 50% of patients after abdominal surgery. Loss of functioning alveolar units and development of atelectasis after abdominal surgery have been recognized as the underlying mechanisms responsible for postoperative hypoxemia. Supplemental Oxygen administration is therefore widely recommended after extubation in the postoperative period, especially in patients with high risk of postoperative respiratory complications. Although oxygen therapy is effective in preventing the vast majority of severe postoperative hypoxemia after extubation in surgical patients, respiratory failure may occur, thus requiring endotracheal intubation and mechanical ventilation or therapeutic use of non-invasive positive pressure ventilation (NPPV). In patients with postoperative hypoxemia (defined as patients with a PaO2/FiO2 ratio <300), application of NPPV was found to decrease the incidence of endotracheal intubation after abdominal surgery. Nevertheless, use of NPPV in the postoperative period is responsible for organizational constraints and increases healthcare utilization.