To explore the effect of low tidal volume on blood loss and gas exchange during laparoscopic hepatectomy

Background & Aims:Liver cancer is an disease that threatening human health .Laparoscopic hepatectomy is more and more widely used.It is very important to reduce the bleeding during laparoscopic hepatectomy.The investigators found that low tidal volume can effectively reduce intraoperative bleeding.The aim of this study was to explore the effect of low tidal volume on blood loss and gas exchange 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.