Abstract / Summary
Abstract Background Prolonged clear fluid fasting (CFF) is associated with adverse metabolic and hemodynamic effects, yet its real‑world duration and clinical relevance in liver transplant (LT) candidates remain unknown. LT recipients are medically fragile and at high risk of periprocedural hemodynamic instability. Although guidelines permit clear liquids until 2 hours before anesthesia, actual CFF duration and its physiological consequences in LT have not been evaluated. Methods In this single‑center prospective study, 99 adults undergoing nonemergency deceased‑donor LT were enrolled. CFF duration was recorded and analyzed primarily as a continuous predictor using restricted cubic splines; median dichotomization (≤ 12 h vs. >12 h) was performed as a secondary, descriptive comparison. As a secondary, exploratory aim, four outcomes were assessed: post-induction hypotension and de novo hyperglycemia, hyperlactatemia and base deficit. Results Median preoperative CFF duration was 12.0 h (IQR 7.0 to 15.8); 3.0% of patients fasted within the recommended 2 hours. Modelled continuously, each additional hour of fasting was associated with 7.1% lower unadjusted odds of post-induction hypotension (OR 0.93 per hour, 95% CI 0.86 to 1.00), attenuating after adjustment (OR 0.93, 95% CI 0.85 to 1.01) and concordant for a composite of hypotension or vasopressor administration (OR 0.92, 95% CI 0.86 to 0.99); no estimate met the Bonferroni-adjusted threshold, and MAP trajectories did not differ. CFF duration showed no association with de novo hyperglycemia, hyperlactatemia or base deficit, including in a full-cohort continuous sensitivity analysis; these exploratory analyses were underpowered. Conclusions In this prospective study of LT recipient, preoperative CFF was substantially longer than recommended. CFF duration showed no significant association with metabolic derangements, though these exploratory analyses were underpowered. Its association with post-induction hypotension was inconclusive; residual confounding cannot be excluded. These findings do not provide evidence against the current 2-hour clear-fluid guideline and highlight a substantial gap between recommended and actual fasting practice; larger multicenter studies with standardized preoperative IV fluid protocols are needed to clarify its clinical consequences. Trial registration: NCT07288281, retrospectively registered on 2025-12-04