Clinical Research Directory

Inclusion Criteria: * Female patients aged between 18 and 65 years. * American Society of Anesthesiologists (ASA) physical status I, II, or III. * Scheduled for elective laparoscopic gynecological surgery (e.g., hysterectomy, myomectomy, sacrocolpopexy). * Planned to undergo general anesthesia with endotracheal intubation. * Expected surgery duration of 2 hours or more. * Body Mass Index (BMI) ≤ 35 kg/m². Exclusion Criteria: * History of moderate-to-severe Chronic Obstructive Pulmonary Disease (COPD), clinically significant interstitial lung disease, or severe restrictive lung disease. * New York Heart Association (NYHA) class III-IV heart failure, Ejection Fraction (EF) \< 35%, or severe valvular disease. * Advanced arrhythmia or hemodynamic instability (requiring high-dose vasopressor support). * History of respiratory failure requiring mechanical ventilation within the past 4 weeks. * Clinically or radiologically confirmed lower respiratory tract infection (e.g., pneumonia) within the past 1 month. * Presence of thoracic deformity, large surgical dressings, severe subcutaneous emphysema, or any condition that hinders lung ultrasound evaluation. * Pre-existing significant atelectasis or lung consolidation (defined as a score of 3 for consolidation or ≥2 zones with a score of ≥2 on preoperative LUS). * Expected inability to perform the 24-hour postoperative ultrasound measurement (e.g., due to early discharge).