Comparison of Different Ventilation Modes in Video-Assisted Thoracoscopic Lung Resection

One-lung ventilation (OLV) is required for video-assisted thoracoscopic surgery (VATS) lung resection, but it exposes the dependent lung to atelectasis, high driving pressures, and oxidative stress, and is associated with postoperative pulmonary complications. Volume-controlled ventilation (VCV) and pressure-controlled ventilation (PCV) are the conventional modes used during OLV. Flow-controlled ventilation (FCV) is a newer mode that delivers a constant gas flow during both inspiration and expiration through a narrow-bore endotracheal tube, and has been proposed to improve gas distribution and reduce mechanical stress on the lung. This prospective observational study evaluates oxygenation and respiratory mechanics in adult patients undergoing elective VATS lung resection under OLV. The ventilation mode used for each patient is determined by the attending anaesthesiologist as part of routine clinical care, independently of the study; investigators do not participate in any aspect of patient management and collect data through observation only. Patients are grouped according to the mode used in clinical practice (FCV, VCV, or PCV). The primary outcome is arterial oxygenation (PaO₂) at 30 minutes of OLV. Secondary outcomes include dynamic lung compliance, driving pressure, mechanical power, and haemodynamic parameters recorded at predefined intervals. A total of 120 patients (ASA I-III, GOLD stage 1-2) are planned for enrolment.

Inclusion Criteria: * -Age 18 years and older * American Society of Anesthesiologists (ASA) physical status I, II, or III * Scheduled for elective lung resection by video-assisted thoracoscopic surgery (VATS) * Planned one-lung ventilation * GOLD 2026 group 1 or group 2 * Planned total intravenous anesthesia (TIVA) * Willing to participate and provides written informed consent Exclusion Criteria: * ASA physical status IV or older * Emergency surgery * Previous neoadjuvant chemotheraphy or radiotherapy * GOLD 2026 group 3 or group 4 * Pneumothorax, pleural effusion or interstitial lung disease * One-lung ventilation cannot be clinically maintained * Planned thoracotomy * Incomplete data * Refusal to participate