acute cholangitis

Acute cholangitis results from obstruction of the common bile duct—most commonly by choledocholithiasis—followed by bacterial infection of stagnant bile, typically with enteric organisms such as E. coli, Klebsiella, Enterococcus, and Bacteroides ascending from the duodenum via the sphincter of Oddi. Other causes include biliary strictures, malignancy (e.g., cholangiocarcinoma, pancreatic cancer), primary sclerosing cholangitis, and post-ERCP complications. The obstruction raises intraductal pressure, promoting bacterial translocation into the bloodstream and increasing risk of sepsis. Clinically, Charcot's triad (fever, jaundice, RUQ pain) is present in about 50-70% of cases; the more severe Reynolds' pentad (triad plus altered mental status and hypotension) indicates suppurative cholangitis and higher mortality. Labs typically show leukocytosis, elevated alkaline phosphatase, GGT, direct bilirubin, and mildly elevated transaminases (cholestatic pattern). Ultrasound may show bile duct dilation and stones, but MRCP or ERCP provides definitive diagnosis and can be therapeutic. Management includes IV fluids, broad-spectrum antibiotics covering gram-negative and anaerobic organisms (e.g., piperacillin-tazobactam), and urgent biliary decompression via ERCP with sphincterotomy and stone extraction/stent placement; percutaneous transhepatic cholangiography or surgical drainage are alternatives if ERCP fails. Delayed treatment can lead to sepsis, liver abscess, or death, making early recognition crucial. Differentiating cholangitis from cholecystitis is key: cholecystitis typically lacks jaundice and involves gallbladder inflammation without necessarily involving bile duct obstruction.