The incidence of lung cancer in China is increasing year by year. Currently, the treatment primarily based on video-assisted thoracoscopic surgery (VATS) is still considered the optimal approach for early-stage non-small cell lung cancer. The widespread application of traditional one-lung ventilation (OLV) technology not only achieves effective lung isolation, but also facilitates exposure of the surgical field during thoracoscopic surgery, making it more convenient for surgeons to operate. However, the occurrence of hypoxemia during one-lung ventilation may pose a risk to patient safety.

One-lung ventilation can lead to increased intrapulmonary shunt, ventilation/perfusion (V/Q) mismatch, and ischemic-hypoxic lung injury. Hypoxemia is the major problem during one-lung ventilation. Postoperative pulmonary complications (PPCs) are among the major complications following thoracic and general anesthesia surgeries, including atelectasis, pneumonia, and respiratory failure, which significantly prolong hospital stay and increase mortality.

Low tidal volume lung-protective ventilation strategies have been widely implemented. Additionally, permissive hypercapnia, reducing peak airway pressure to minimize barotrauma, and decreasing FiO₂ all help reduce pulmonary complications.Recently, researchers have focused on optimizing ventilation strategies during OLV, such as using PEEP or low VT ventilation alone or in combination, or exploring different combinations of tidal volume and respiratory frequency under consistent minute ventilation (VE), aiming to balance lung protection and oxygenation, reduce complications, and improve patient outcomes.

However, to date, there is still no gold standard tidal volume ventilation strategy for reducing pulmonary complications in patients undergoing lung resection.

Inclusion Criteria:

• Age > 50 years.
• ASA physical status I-II.
• The cardiopulmonary and other vital organ functions are basically normal, and the patient is able to tolerate surgery.
• Ariscat score > 26.
• Informed consent has been obtained.

Exclusion Criteria:

• Patients who refuse to participate in the clinical trial, or have cognitive impairment or impaired ability to understand and express themselves.
• ASA physical status ≥ III.
• Patients with congestive heart failure, severe aortic stenosis, or extensive pleural adhesions.
• Patients with severe psychiatric disorders or allergy to anesthesia-related medications.
• Patients with severe organ dysfunction such as the liver or kidney dysfunction.

Patients undergoing video-assisted lung surgery