Association between intraoperative hyperoxia and liver function in patients undergoing hepatectomy: a multicenter observational study

PURPOSE: Oxygen (O₂) is recognized as both a "friend and foe" to various organs, with emerging evidence suggesting potential adverse effects of hyperoxia on the liver. This study aimed to evaluate whether a high intraoperative partial pressure of arterial oxygen (PaO₂ ≥ 300 mmHg) during hepatectomy is associated with postoperative liver injury. METHODS: A comparative analysis was conducted on patients undergoing hepatectomy at a university hospital, stratified by intraoperative PaO₂ levels (≥ 300 mmHg vs. <300 mmHg). Primary outcomes included markers of liver function impairment, specifically elevated levels of alanine aminotransferase (ALT), aspartate transaminase (AST), and total bilirubin (Tbil), reduced plasma albumin levels, as well as increased international normalized ratio (INR), prothrombin time (PT). Secondary outcomes encompassed hospital length of stay (LOS) and postoperative complications (Clavien-Dindo classification). Subgroup analyses were performed based on Child‒Pugh score (≥ 7), age (≥ 65 years), surgical approach (laparoscopic), and surgery duration. Additionally, findings were validated in a prospective cohort of 76 patients. RESULTS: The study included 292 patients who underwent hepatectomy between January 2021 and December 2021. All patients survived through hospital discharge. There were no cases diagnosed as post-hepatectomy liver failure. Postoperative changes in ALT, AST, Tbil, albumin levels, and INR, PT were comparable between the high and low PaO₂ groups. No significant differences were observed in hospital LOS and postoperative complications. Subgroup analyses yielded consistent results. These findings were further corroborated in the prospective validation cohort. CONCLUSIONS: The findings suggest that intraoperative high PaO₂ (≥ 300 mmHg) is not associated with adverse effects on postoperative liver injury in patients undergoing hepatectomy.