Postoperative pulmonary complications (PPCs) following upper abdominal surgery are common, and are associated with prolonged hospital stay even for cardiopulmonary healthy patients. The development of atelectasis and the unequal distribution of perfusion-ventilation during anesthesia and surgery, and perhaps the reappearance of these disturbances after surgery, are the main hypotheses used to explain postoperative hypoxemia and pulmonary complications. Atelectasis may be increased by using a Kent retractor, which retracts the abdominal wall and compresses the lung. This study evaluated the effect of preventive intraoperative positive end-expiratory pressure (PEEP) on perioperative oxygenation and complications in patients who receive gastrectomy with a Kent retractor.

Thirty eight cardiopulmonary healthy patients were randomly allocated to receive 0 (control), 5 or 10 cmH2O of PEEP during surgery. Arterial blood was obtained to evaluate arterial oxygenation and the unequal distribution of perfusion-ventilation by analyzing arterial oxygen tension and alveolar-arterial oxygen tension differences ((A-a)Do2) during the perioperative period. Pulmonary function and complications were also evaluated.

Intraoperative arterial oxygenation improved for all patients receiving 5 or 10 cm H2O PEEP. In the control group, there was statistically significant decrease in PaO2 and increase in (A-a)Do2 after Kent retractor was applied, but the others did not show this effect (P<0.05). No differences in postoperative oxygenation, the incidence of pulmonary complications or pulmonary function were observed between the three groups.

The application of PEEP was effective at improving oxygenation, and at preventing atelectasis and an unequal distribution of perfusion-ventilation during gastrectomy with a Kent retractor. However, the effects of PEEP did not extend beyond surgery.