The purpose of this study is to determine the influence of moderate FiO2 and the lung protective ventilation on postoperative pulmonary complications following hepatic resection surgery.

Inclusion Criteria:

• ASA 1~2,Planned intrabdominal hepatic resection surgery;
• Expected duration 2 hours to 6 hours;
• Age 40 yr to 70 yr);
• BMI 18-26.9kg/m2
• Risk of postoperative pulmonary complications (Arozullah score ≥2);

Exclusion Criteria:

• Noninvasive ventilation in the last 30 days;
• Recent history of pneumonia, ALI/ARDS (in the last 30 days);
• History of pulmonary resection;
• History of neuromuscular disease;
• Child-Pugh>A grade；
• Patient refusal;