The incidence of postoperative pulmonary complications (PPCs) after thoracic surgery is as high as 30-50% [1-6], which is the main cause of postoperative morbidity, death and prolonged hospital stay. Optimization of risk factors in PPCs procedures is the focus of current research. Double lumen bronchial tube (DLT) is a commonly used lung isolation method for adult patients. It has the advantages of good lung isolation effect, sufficient exposure of the surgical field and easy to attract secretions in the airway. However, there are still some deficiencies in clinical precise positioning, long-term continuous detection during operation, early detection of catheter displacement and other emergencies. Continuous intra-airway monitoring is the main advantage of visual double-lumen bronchial catheter. It can quickly and easily determine the position of the catheter and quickly adjust the displacement, and timely and effectively clean up the secretion in the airway, which is conducive to the analysis and treatment of intraoperative hypoxemia. Whether these potential advantages can reduce the incidence of PPCs deserves our in-depth discussion. The research group randomly divided the patients who were scheduled to undergo thoracoscopic radical resection of lung cancer in the Union Hospital affiliated to Fujian Medical University into the test group (lung isolation with visible double-lumen bronchial catheter, continuous intra-airway monitoring and intervention) and the control group: (Pulmonary isolation was performed with visual double-lumen bronchial catheter, and only intra-airway video was performed without monitoring. The effect of continuous intra-airway monitoring under visual double-lumen bronchial catheter on postoperative complications of lung surgery was evaluated by Melbourne evaluation scale.

Inclusion Criteria:

• 1. Age 18-80 years, BMI 18.5-28 kg/m2, male or female
• 2. Patients who are to undergo unilateral thoracoscopic resection of more than three lung segments or lobectomies
• 3. Patients who can be extubated with 35# and 37# double-lumen bronchial catheters after pre-anesthetic evaluation
• 4. Subjects voluntarily sign the informed consent form for this trial.
• 5. Patients or their caregivers are able to fill out the survey form and can correctly understand and cooperate with the postoperative rehabilitation instructions of the medical staff.
• 6. Patients have SPO2 ≥ 96% when inhaling air preoperatively

Exclusion Criteria:

• 1. Patients with limited ability to cooperate with the study, such as the presence of cognitive dysfunction, mental illness, speech impairment or severe visual impairment or hearing impairment
• 2.ASA ≥IV
• 3. difficult airway, abnormal tracheal development, main airway stenosis, tumor, tracheoesophageal fistula
• 4. Complex sleeve pneumonectomy, unilateral total pneumonectomy, bilateral lung surgery
• 5. Preoperative anemia, Hb≤100g/L
• 6. Serum albumin ≤ 35g/L