Effect of Low Tidal Volume on Blood Loss During Laparoscopic Hepatectomy

Inclusion Criteria: 1. Aged from 18 to 70 years old; 2. American association of anesthesiologists(ASA) score I to III; 3. Ability to adhere to the study schedule; 4. Ability to provide informed consent and complete all study assessments; 5. Patients undergoing selective surgery of laparoscopic hepatectomy. Exclusion Criteria: 1. The New York Heart Association classification(NYHA) III to IV; 2. Chronic obstructive pulmonary disease,respiratory failure, patients after thoracic surgery. 3. BMI\>32Kg/m2; 4. Abnormal in blood coagulation function; 5. Patients with mental disease; 6. Patients with neuromuscular disease; 7. Concurrent enrollment in another Randomized controlled trial(RCT); 8. Absence of written informed consent.