Inclusion Criteria:  - patients with ASA I-III physical status  patients between the ages of 18-75  patients who will undergo liver resection  Exclusion Criteria:  - patients with ASA physical status of IV  patients with clinically significant cardiovascular, respiratory, renal or metabolic disease, ischemic cerebrovascular disease  Patients who have BMI >30  Patients who aged >75 years  Patients with intellectual disability  Patients who will have intraoperative surgical complications  Patients who will need for postoperative ventilation  Patients who have methemoglobinemia after intravascular dye injection