Association of Preoperative Fasting Strategy with Postoperative Inflammatory–Nutritional Trajectories and Clinical Outcomes Following Hepatobiliary Surgery: A Retrospective Cohort Study

Abstract

Background/Objectives: Major hepatobiliary surgery elicits substantial inflammatory and catabolic stress, which may be aggravated by prolonged preoperative fasting. We evaluated the association of preoperative fasting strategy with postoperative inflammatory–nutritional trajectories and clinical outcomes after elective hepatobiliary surgery. Methods: This retrospective cohort study included 1409 adults who underwent elective hepatobiliary surgery between January 2020 and December 2025. Patients were classified according to the interval from last caloric intake to anesthesia induction as <6 h or ≥6 h. All patients in the <6 h group were managed under an Enhanced Recovery After Surgery (ERAS) pathway with preoperative carbohydrate loading. Postoperative trajectories of the C-reactive protein-to-albumin ratio (CAR), neutrophil-to-lymphocyte ratio (NLR), and prognostic nutritional index (PNI) were analyzed using linear mixed-effects models. Results: The <6 h group showed more favorable postoperative CAR and NLR trajectories (group × time interaction, both p < 0.001). Although the overall PNI trajectory also differed between groups (p = 0.003), between-group differences were inconsistent across individual time points. In fully adjusted models, longer fasting duration was associated with higher postoperative day (POD) 3 CAR and NLR, but not with PNI. After additional adjustment for ERAS implementation, the CAR and NLR associations were attenuated and no longer statistically significant. Clinical outcomes did not differ between groups. Conclusions: An ERAS-associated shortened-fasting strategy incorporating preoperative carbohydrate loading was associated with more favorable postoperative CAR and NLR trajectories. These findings reflect associations with the overall perioperative strategy rather than an independent effect of fasting duration.