Effect of Automated Intraoperative Lung Recruitment Maneuvers on Atelectasis in Patients Undergoing Major Laparoscopic Surgery: A Randomized Controlled Trial

This study is a prospective, randomized, single-center controlled clinical trial designed to evaluate the effects of automated intraoperative lung recruitment maneuvers on perioperative atelectasis and postoperative pulmonary complications in patients undergoing major laparoscopic colorectal cancer surgery under general anesthesia.

Despite its minimally invasive nature, laparoscopic colorectal surgery is associated with significant perioperative respiratory challenges. Pneumoperitoneum, Trendelenburg positioning, and prolonged operative duration may reduce functional residual capacity, impair respiratory mechanics, and promote intraoperative atelectasis. Atelectasis developing during general anesthesia can persist into the postoperative period and is a major contributor to postoperative pulmonary complications.

Although lung recruitment maneuvers are frequently used to improve lung aeration, manual application lacks standardization and reproducibility. Automated lung recruitment maneuvers delivered by modern anesthesia ventilators may provide a standardized and controlled approach to lung recruitment. Lung ultrasonography is a reliable, bedside, radiation-free imaging modality that allows real-time assessment of lung aeration and detection of atelectasis without the need for patient transport.

After confirmation of eligibility and arrival in the operating room, participants will be randomized in a 1:1 ratio to either an automated lung recruitment maneuver group or a control group receiving standard mechanical ventilation without lung recruitment. Standard intraoperative monitoring will be applied to all patients.

Lung ultrasonography will be used to assess lung aeration and detect atelectasis at predefined perioperative time points, including preoperative baseline assessment, intraoperative evaluation, and postoperative follow-up. Lung ultrasound scores will be used to quantify the degree of aeration loss.