Postoperative pulmonary complications (PPC) emerge as a major risk that determines the morbidity and mortality of patients after surgery. PPCs affect the length of hospital stay and increase health costs. Because of this reason, it is important to predict PPCs before surgery. There are many studies on scoring systems that can be effective in predicting PPCs. The most frequently used ones are the Assess Respiratory Risk in Surgical Patients in Catalonia (ARISCAT) risk index, the Nutritional Risk Score (NRS), and the American Society of Anesthesiologist (ASA) score. ARISCAT risk index is mostly evaluated in operations performed other than thoracic surgery. Since the thoracic wall, mediastinum or lungs are directly intervened in thoracic surgery operations, the expected PPCs in these patients may be different from those expected in other surgical groups. Therefore, the ARISCAT risk index may be insufficient to evaluate PPCs in thoracic surgery.

Inclusion Criteria:

• Patients who will undergo elective thoracotomy or video assisted thoracic surgery with general anesthesia
• BMI < 35 kg/m2
• Age 18 - 75 years old
• Expected operative time more than 60 minutes

Exclusion Criteria:

• History of lung surgery
• Advanced lung-heart disease
• Having a previous COVID-19 pneumonia

Patients aged 18-75 years who are scheduled for elective thoracotomy or VATS, who have not had previous thoracic surgery, and without advanced lung and heart disease.