IntroductionAcute cholangitis (AC) is a clinical condition that requires prompt medical management with IV fluids, antibiotics, and biliary drainage (BD). The optimal timing for BD remains unclear.AimTo investigate the effect of biliary drainage timing on clinical outcomes in AC.Material and methodsWe conducted a retrospective study of patients with AC admitted to the ICU using the Multiparameter Intelligent Monitoring in Intensive Care III (MIMIC-III) database. Emergency department to BD time, hospital death, length of stay (LOS), and severity scores were extracted from the database. We investigated the effect of BD timing on mortality rates, persistent organ failure, and LOS.ResultsA total of 177 patients were included; 50% were males; median age was 75 years, in-hospital mortality was 9.6%, mean time-to-ERCP was 32 h (range: 0.42–229.6) with 76% meeting the Tokyo Guidelines (TG13) criteria for severe cholangitis, and median Simplified Acute Physiology Score II (SAPS II) was 42 (IQR: 33–51). Using 24 h as a cut-off, patients who underwent BD ≤ 24 h had less persistent organ failure (OR = 0.49; 95% CI: 0.26–0.96, p = 0.040), shorter ICU LOS (3.25 vs. 4.95 days, p = 0.040), shorter hospital LOS (7.71 vs. 13.57 days, p = 0.001), but no difference in either in-hospital mortality (OR = 0.47, 95% CI: 0.17–1.29, p = 0.146) or 28-day mortality (OR = 0.61, 95% CI: 0.24–1.53, p = 0.297).ConclusionsIn critically-ill patients with acute cholangitis, early biliary drainage ≤ 24 h is associated with less persistent organ failure and shorter length of stay but had no effect on patient survival.