Positive end-expiratory pressure and postoperative complications in patients with obesity: a review and meta-analysis

Abstract

Objective: In patients with obesity, use of positive end-expiratory pressure (PEEP) > 5 cm H2O (centimeters of water) has been shown to prevent intraoperative atelectasis. This study compares the rate of postoperative pulmonary complications (PPCs) associated with PEEP > 5 cm H2O and PEEP ≤ 5 cm H2O in patients with obesity who underwent surgery under general anesthesia with mechanical ventilation. Methods: This study searched Medline, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) using the terms “PEEP,” “anesthesia,” and “ventilation.” Cochrane ReviewManager (RevMan) version 5 was used for data analysis. The primary outcome was a composite of PPCs, including atelectasis, pneumonia, pneumothorax, and acute respiratory failure. Results: The initial search identified 903 titles and abstracts, and 4 randomized controlled trials were included for analysis. We included a total of 2116 participants from four randomized controlled trials that compared PEEP ≤ 5 cm H2O with PEEP > 5 cm H2O in adult patients with obesity. There was no statistically significant difference in PPCs between the PEEP ≤ 5 cm H2O and PEEP > 5 cm H2O groups (risk ratio = 2.21, 95% CI: 0.41-11.83; p = 0.35). However, a significant heterogeneity was found within included studies (I2 = 53%). Conclusions: It is unclear whether PEEP > 5 cm H2O improves the postoperative clinical outcome in patients with obesity, which is in contrast to previously established evidence that it reduces atelectasis in patients with obesity.