Grade III (severe) acute cholangitis	Grade II (moderate) acute cholangitis	Grade I (mild) acute cholangitis
Grade III acute cholangitis is defined as acute cholangitis that is associated with the onset of dysfunction ≥ 1 of the following organs/systems: cardiovascular dysfunction: hypotension requiring dopamine ≥ 5 μg/kg per minute, or any dose of noradrenaline; neurological dysfunction: disturbance of consciousness; respiratory dysfunction: PaO2/FiO2 ratio < 300; renal dysfunction: oliguria, serum creatinine > 2.0 mg/dL; hepatic dysfunction: PT‐INR > 1.5; haematological dysfunction: platelet count < 100000/mm3.	Grade II acute cholangitis is associated with any 2 of the following conditions: abnormal WBC count (> 12,000/mm3, < 4000/mm3); high fever (≥ 39 °C); age (≥ 75 years); hyperbilirubinaemia (total bilirubin ≥ 5 mg/dL); hypoalbuminaemia (lower limit of normal value × 0.7).	Grade I acute cholangitis does not meet the criteria of Grade III (severe) or Grade II (moderate) acute cholangitis at initial diagnosis.