A Simplified Physiology-Laboratory Score (PLS4) for Early Risk Stratification in Acute Cholangitis

Objectives: Acute cholangitis is a common biliary infection in the emergency department (ED) that can progress rapidly to septic shock and multiorgan dysfunction. The Tokyo Guidelines 2018 (TG2018) is the current reference standard for severity assessment but may be cumbersome during the initial ED encounter. We aimed to develop a simplified physiology-laboratory score (PLS4) computable from four routine bedside variables and to compare its early risk-stratification performance with TG2018. Materials and Methods: This single-center retrospective observational cohort study included 482 adult patients with acute cholangitis (International Classification of Diseases, 10th Revision code K83.0) presenting to a tertiary university hospital ED between January 2016 and December 2021. Primary outcomes were ICU admission, vasopressor use, and prolonged hospital stay (length of stay ≥ 14 days); intubation was analyzed as an exploratory outcome. PLS4 assigned 1 point each for albumin < 3.5 g/dL, systolic blood pressure ≤ 100 mmHg, heart rate ≥ 100/min, and prothrombin time-international normalized ratio ≥ 1.2 (range 0-4). Discrimination was assessed by receiver operating characteristic curves, with bootstrap 95% confidence intervals and bootstrap optimism-corrected internal validation. Results: ICU admission occurred in 81 patients (16.8%), vasopressor use in 53 (11.0%), and prolonged stay in 111 (23.0%). The areas under the curve (AUCs) for ICU admission were 0.850 for TG2018 and 0.800 for PLS4 (p = 0.116), and the optimism-corrected AUC of PLS4 was 0.779. For vasopressor use, which is part of the TG2018 grade III definition, the AUCs were 0.936 and 0.843. When PLS4 was added to TG2018, the AUC for ICU admission increased to 0.886. At PLS4 ≥ 3, specificity reached 0.978 for ICU admission and 0.970 for vasopressor use, with event rates rising stepwise from 5.96% to 100% and 2.55% to 90.0%, respectively. Conclusions: In this single-center derivation study, PLS4 showed high specificity and added prognostic information to TG2018. It should be validated in other centers before clinical use.