Efficacy of positive expiratory pressure in the prevention and treatment of postoperative pulmonary complications following thoracic and abdominal surgery. A systematic review and meta-analysis.

Postoperative pulmonary complications (PPCs), including atelectasis, pneumonia, and respiratory failure, are common after thoracic and upper abdominal surgery and are associated with increased morbidity, longer hospital stays, and higher costs. This systematic review and meta-analysis investigated whether positive expiratory pressure (PEP) devices reduce PPCs after thoracic or upper abdominal surgery compared with continuous positive airway pressure (CPAP), usual care/no intervention, or other non-CPAP respiratory treatments. We searched major databases and included randomized controlled trials. A total of 12 studies were included, and 7 contributed to the meta-analysis. Across comparator-stratified analyses, PEP did not demonstrate a consistent reduction in PPCs. Compared with usual care/no intervention, pooled estimates showed no significant benefit, and results were similarly inconclusive when PEP was compared with other non-CPAP treatments; evidence vs. CPAP was limited to a single small trial. The overall certainty of evidence was low due to methodological limitations and heterogeneity in outcome definitions and intervention protocols. Overall, current evidence does not support routine use of PEP devices as a primary strategy to prevent PPCs after thoracic or upper abdominal surgery. Further well-designed trials are needed to clarify whether specific patient subgroups or standardized protocols may benefit.