Postoperative pulmonary complications (PPCs) are a leading cause of morbidity and mortality following upper abdominal surgery. Applying either noninvasive ventilation (NIV) or continuous positive airway pressure (CPAP) in the early postoperative period is suggested to prevent PPC. We aimed to assess whether postoperative NIV or CPAP or both prevent PPCs compared with standard care in adults undergoing upper abdominal surgery, including in those identified at higher PPC risk. Additionally, the different interventions used were evaluated to assess whether there is a superior approach.