Inclusion Criteria:  Adult patients 18 years of age or older who underwent living-donor liver transplantation for end-stage liver failure  Exclusion Criteria:  A score of 26 or higher on the model for end-stage liver disease (MELD) scale In case of endotracheal intubation when entering the operating room If hepatic encephalopathy is stage 3 or higher at the time of admission to the operating room When the arterial blood partial pressure (PaO2)/inhaled oxygen fraction (FiO2) ratio is less than 200 on the Arterial Blood Gas Analysis (ABGA) before the end of the living liver transplantation operation Preoperative chest X-ray examination or chest computed tomography shows pulmonary edema If patients is diagnosed with hepatopulmonary syndrome before surgery