Intraoperative Mechanical Ventilation Strategies and Postoperative Pulmonary Outcomes

Intraoperative mechanical ventilation is essential for maintaining adequate gas exchange during general anesthesia, yet the way ventilation is delivered can influence pulmonary function during the postoperative period. General anesthesia, neuromuscular blockade, patient positioning, and surgical manipulation alter respiratory mechanics and promote reductions in functional residual capacity, alveolar collapse, and ventilation–perfusion mismatch. These physiological changes may increase susceptibility to postoperative pulmonary complications, including atelectasis, pneumonia, hypoxemia, respiratory failure, and acute respiratory distress syndrome. Growing recognition of ventilator-induced lung injury has shifted intraoperative respiratory management toward lung-protective strategies designed to minimize mechanical stress while preserving adequate ventilation and oxygenation. Lower tidal volumes based on predicted body weight, appropriate positive end-expiratory pressure (PEEP), controlled airway and driving pressures, and selective recruitment maneuvers form the principal components of contemporary protective ventilation. Evidence indicates that these parameters are closely interconnected, and modifying a single ventilatory variable without considering its effect on respiratory mechanics may provide limited clinical benefit. Continuous assessment of airway pressures, respiratory-system compliance, oxygenation, carbon dioxide elimination, and driving pressure enables ventilator settings to be modified in response to physiological changes occurring throughout surgery. Advanced techniques such as electrical impedance tomography, lung ultrasound, and volumetric capnography may further characterize regional ventilation, alveolar recruitment, and changes in lung volume. Increasing attention has also been directed toward individualized ventilation, particularly PEEP titration according to respiratory compliance, driving pressure, or regional ventilation rather than the routine application of fixed settings. Such approaches are particularly relevant in patients with obesity, during laparoscopic procedures, and during one-lung ventilation, where respiratory mechanics may change considerably. The relationship between intraoperative ventilation and postoperative pulmonary outcomes therefore depends on the combined mechanical effects of tidal volume, pressure, PEEP, recruitment, patient characteristics, and surgical conditions, supporting a physiologically guided approach to intraoperative respiratory management.