A variety of reasons lead to a sharp increase in lactic acid levels in patients undergoing liver resection, while leading to hyperlactic acidemia, resulting in decreased cardiac output, elevated blood potassium, and response to catecholamines and insulin Damage, increased risk of kidney damage, poor recovery of liver function, decreased immune function, and prolonged hospital stay. Sodium bicarbonate Ringer injection does not contain lactic acid. HCO3- is metabolized by acid-base neutralization in body fluids, and 90% is CO2 The form is excreted from the body by breathing, and only 10% HCO3- is metabolized by the kidney, without the burden of liver metabolism. Physiological concentration of Cl- avoids perchloric acidosis and kidney damage; physiological concentration of Ca2+ and Mg2+ help maintain the body's electrolyte balance and reduce stress-related arrhythmia.The smooth development of this study will help refine the intraoperative fluid management strategy, improve the patient's intraoperative tissue perfusion, maintain the body's acid-base and electrolyte balance, reduce postoperative kidney damage, and improve the patient's quality of life.

This study intends to carry out a high-quality clinical research with design specifications, large sample, multi-center, randomized and controlled methods. From October 9, 2020 to October 9, 2022, participants undergoing hepatectomy surgery under general anesthesia will be recruited. Participants will be randomly assigned, in a 1:1 ratio, to receive Sodium bicarbonate Ringer's solution or control (Acetate Ringer's solution). The randomization sequence will be computer-generated, and randomization will be performed in blocks and will be stratified according to participating center. After entering the operating room, the two groups were pre-dilated with sodium bicarbonate Ringer or acetate Ringer (30 min, 8 ml/kg). After the operation started, the two groups of participants were maintained with 4-5 ml/kg/h Ringer's solution during the operation. Blood gas index (but are not limited to these data) at intraoperative will be recorded. At the same time, other dates will be recorded.The participation of each patient is scheduled for 1 month.

Inclusion Criteria:

1. Patients for selective liver surgery under general anesthesia
2. Age > 18 year，BMI 18 - 40 kg/m2，American society of Anesthesiologists (ASA) grade are between I - III
3. Ability to understand, sign informed consent and cooperate with the intervention and evaluation

Exclusion Criteria:

1. Abnormal renal function：blood creatinine (Cr) and / or urea nitrogen (BUN)> upper limit of normal value; Patients with underlying kidney disease; patients with congenital kidney malformations.
2. In patients with respiratory failure, arterial blood oxygen partial pressure (PaO2) < 60 mmHg, or accompanied by carbon dioxide partial pressure (PaCO2)> 50mmHg; blood oxygen saturation (SpO2) < 90%.
3. A history of myocardial infarction within 6 months before the screening period; history of severe circulatory or respiratory diseases; history of autoimmune diseases; patients with mental illness or neurological disorders that cannot be expressed exactly; patients with a history of epilepsy; patients with pulmonary edema or congestive heart failure.
4. Severe hypercalcemia (Ca2+ > 2.75 mmol/L), hypernatremia (Na+ > 155 mmol/L), hyperkalemia (K+ > 5.5 mmol/L), hyperchloremia (Cl- > 110 mmol/L), Hypermagnesium (Mg2+ > 1.25 mmol/L).
5. Patients with a history of hypothyroidism; pregnant or lactating women.
6. Patients with a history of adverse blood transfusion reactions; those who refuse blood transfusions.
7. Participation in other clinical studies within 3 months before admission to this study.
8. The investigator considers it unsuitable for inclusion.