S49 Lactate Levels Don't Lie: A Powerful Predictor in Acute Cholangitis

Introduction: Acute cholangitis is a life-threatening condition that requires timely diagnosis and intervention. The Tokyo Guidelines serve as the primary framework for diagnosing and grading acute cholangitis, incorporating clinical symptoms, inflammatory markers, and imaging findings. However, lactate levels, a widely recognized biomarker is not included in these criteria. Elevated lactate has been associated with poor outcomes in sepsis and critical illness, yet its role in risk stratification for cholangitis remains unexplored. In this study, we aim to evaluate the prognostic significance of lactate in patients with cholangitis. By conducting a propensity-matched cohort analysis, we compare outcomes between patients with normal lactate (0-2 mmol/L) and those with elevated lactate (2-12 mmol/L) to determine whether lactate should be integrated into the Tokyo Guidelines for improved risk assessment and clinical decision-making. Methods: This retrospective propensity-matched cohort study evaluated patients diagnosed with cholangitis using ICD-10 codes, stratified into 2 groups based on lactate levels: 0–2 mmol/L and 2–12 mmol/L. One-to-one matching was performed to minimize confounding, adjusting for demographics (age, sex, race, ethnicity), Charlson Comorbidity Index components (e.g., cardiovascular, pulmonary, hepatic, renal, and oncologic conditions), and clinical variables (albumin levels, fever). Outcomes within 1 month were compared, including mortality, sepsis/bacteremia, intensive care unit admission, vasopressor use, and interventions such as endoscopic retrograde cholangiopancreatography (ERCP), cholecystectomy, and cholecystostomy tube placement. Results: Patients with elevated Lactate levels had worse outcomes in comparison. Mortality: RR 2.659; P < 0.001. Sepsis/Bacteremia: RR 1.182; P < 0.001. Vasopressor Use: RR 1.162; P < 0.001. ICU Admission: RR 0.744; P = 0.072. ERCP: RR 0.886; P = 0.019. Cholecystectomy: RR 0.692; P = 0.003. Cholecystostomy Tube: RR 1.043; P = 0.559. Conclusion: This propensity-matched analysis demonstrates that elevated lactate levels are a strong predictor of adverse outcomes in cholangitis. Patients with lactate 2-12 mmol/L have significantly higher mortality, sepsis rates, and vasopressor use, yet are less likely to undergo ERCP or cholecystectomy. Given these findings, lactate should be considered for inclusion in the Tokyo Guidelines as a key risk stratification tool. Future prospective studies are warranted to establish optimal lactate thresholds for guiding management decisions in cholangitis.