Acute cholangitis is a potentially life-threatening bacterial infection of the biliary tree. It typically occurs as a result of a combination of biliary tract obstruction and elevated intrabiliary pressure, which facilitates the systemic translocation of bacteria from the biliary system into the bloodstream.

The primary cause of acute cholangitis is biliary tract obstruction. The most common etiologies include:

• Choledocholithiasis: Gallstones migrating into and obstructing the common bile duct (accounting for ~60% of cases).


• Benign and Malignant Strictures: Biliary tract narrowing from post-operative scarring, primary sclerosing cholangitis (PSC), or compression by pancreatic, biliary, or hepatic tumors.


• Instrumentation/Intervention: Post-endoscopic retrograde cholangiopancreatography (ERCP) contamination or occluded indwelling biliary stents.

Under physiological conditions, bile flow is sterile due to continuous anatomical clearance and immunological defenses. The pathophysiology of acute cholangitis relies on two factors:

1. Biliary Obstruction: Leads to bile stasis, creating a nidus for bacterial proliferation.


2. Elevated Intrabiliary Pressure: Obstruction increases pressure within the biliary system (>20 cm H2O). This high pressure disrupts the tight junctions between hepatocytes and cholangiocytes, causing biliary-venous and biliary-lymphatic reflux. Bacteria and endotoxins then enter the systemic circulation, leading to systemic inflammatory response syndrome (SIRS), bacteremia, and septic shock.

• Prevalence: Relatively rare in the general population but accounts for up to 10% of patients admitted with acute abdominal pain related to gallstone disease.
• Age/Gender: Typically presents in patients aged 50–70 years. There is no significant gender predisposition, though men are slightly more prone to malignant causes and women to gallstone-related etiologies.

• History of gallstones or cholelithiasis
• Prior episodes of acute cholangitis or cholecystitis
• History of biliary interventions (ERCP, stent placement)
• Hepatobiliary malignancies (e.g., cholangiocarcinoma, pancreatic adenocarcinoma)
• Anatomical abnormalities or strictures of the biliary tract
• Immunosuppression

• Vital Signs: High fever (>38.5°C), tachycardia (>100 bpm), tachypnea, and hypotension.
• Inspection: Scleral icterus, cutaneous jaundice, and signs of dehydration.
• Palpation: RUQ tenderness; hepatomegaly or a palpable gallbladder may be present. Guarding is typically localized unless generalized peritonitis has developed.

• A. Clinical Assessment: Assessment of Tokyo Guidelines (TG18/TG13) criteria, which incorporate signs of systemic inflammation, cholestasis, and imaging confirmation of biliary obstruction.
• B. Laboratory Testing: Evaluates systemic infection, hepatic dysfunction, and organ failure.
• C. Imaging Studies: Identifies ductal dilation, stones, or strictures.
• D. Functional Tests: None in the acute phase.
• E. Biopsy Findings: Contraindicated due to risk of bacteremia and localized peritonitis.
• F. Genetic Testing: Not indicated.
• G. Differential Diagnosis: Differentiating from other acute abdominal pathologies.

Complete Blood Count (CBC)
Type: Blood Test
Purpose: Assess for infection and systemic inflammatory response.
Expected Findings: Leukocytosis (WBC >11,000/µL) or leukopenia (<4,000/µL) with a left shift; thrombocytopenia in severe sepsis.
Interpretation: Reflects systemic infection severity and marrow response. Liver Function Tests (LFTs)
Type: Blood Test
Purpose: Evaluate for cholestasis and hepatic injury.
Expected Findings: Elevated Total Bilirubin (>2.0 mg/dL), elevated Alkaline Phosphatase (ALP >1.5x upper limit of normal), elevated Gamma-Glutamyl Transferase (GGT), and mild-to-moderate elevation in transaminases (AST/ALT).
Interpretation: Elevated bilirubin and ALP confirm a cholestatic pattern indicating biliary tract obstruction. Blood Cultures
Type: Blood Test
Purpose: Identify causative circulating microorganisms.
Expected Findings: Positive growth of enteric pathogens (e.g., E. coli, Klebsiella).
Interpretation: Confirms bacteremia, directing targeted antibiotic therapy.