Effect of driving pressure-guided individualised positive end-expiratory pressure on postoperative atelectasis in patients with morbid obesity: study protocol of a randomised controlled trial

Atelectasis is a common postoperative complication in patients with obesity, contributing to respiratory insufficiency, pneumonia and poor clinical outcomes. Studies have shown that driving pressure (DP)-guided individualised positive end-expiratory pressure can improve respiratory mechanics and oxygenation, while also reducing the incidence of atelectasis and other postoperative pulmonary complications (PPCs). However, the effect of this ventilation strategy on patients with morbid obesity remains unclear. The trial presented here aims to use lung ultrasound to evaluate the effect of DP-guided individualised positive end-expiratory pressure (PEEP) on postoperative atelectasis in patients with obesity undergoing bariatric surgery. This single-centre, randomised, controlled, single-blind study will enrol 52 participants with morbid obesity scheduled for laparoscopic bariatric surgery from 1 March 2024, to 30 April 2025. They will be randomly assigned in a 1:1 ratio to one of two groups: (1) the DP group, where participants will receive dynamic individualised PEEP guided by DP and (2) the fixed PEEP group, where participants will receive a PEEP of 8 cmH2O. The primary outcome is the lung ultrasound score 30 minutes after extubation. Secondary outcomes include the lung ultrasound score on postoperative day 1, the incidence and severity of PPCs within 3 days after surgery, the intraoperative partial pressure of arterial oxygen, DP, static lung compliance, mechanical power, the incidence of hypotension during titration and the dosage of vasoactive drugs. This study has been approved by the Ethics Committee of The First Affiliated Hospital of Shandong First Medical University (YXLL-KY-2023(144)). The trial results will be published in peer-reviewed journals and at conferences. https://clinicaltrials.gov/; NCT06181279.