Effect of Inspired Oxygen Concentration on Postoperative Atelectasis After VATS Lobectomy

This study aims to investigate whether using 50% FiO₂ during one-lung ventilation, compared with 100% FiO₂, reduces postoperative atelectasis in the non-dependent (healthy) lung of patients undergoing VATS pulmonary lobectomy, based on individualized PEEP titration. This is a single-center, prospective, assessor- and patient-blinded randomized controlled trial. A total of 100 patients (50 per group, including a pilot phase of 10 per group) will be enrolled and randomized 1:1 to the high-oxygen group (FiO₂=100%) and the low-oxygen group (FiO₂=50%). The primary endpoint is the percentage of atelectasis volume in the non-operated lung relative to the total non-operated lung volume, assessed by CT at 60±10 minutes after tracheal extubation.