Individualized Positive End-Expiratory Pressure (PEEP) on Oxygenation, Hemodynamics, and Early Postoperative Atelectasis in Laparoscopic Bariatric Surgery

Obesity is a major health problem, and the incidence is increasing worldwide. So far, the only treatment for morbid obesity with good long-term results is bariatric surgery. Obese patients have unique respiratory physiology and ventilatory mechanics characteristics. Their lung function is impaired due to the reduction of oxygen reserve, functional residual capacity, and lung compliance. In addition, they frequently present with respiratory comorbidities, which increases the risk of developing postoperative pulmonary complications (PPCs) such as atelectasis especially after procedures under general anesthesia. Atelectasis has been hypothesized as a main cause of postoperative hypoxemia. To reduce the incidence of atelectasis, positive end-expiratory pressure (PEEP) and recruitment maneuvers are used as a protective lung strategy to improve gas exchange and lung mechanics through reopening collapsed alveoli and maintaining the aeration of lungs. Application of PEEP may also eliminate auto-PEEP without increasing plateau pressure.