Pathophysiology
1) partial or complete obstruction of the biliary tree with resulting bile stasis and secondary bacterial or microbial infection of the biliary tree Causes – 2) common bile duct stones 3) benign biliary stricture (primary sclerosing cholangitis) 4) malignancy (head of pancreas adenocarcinoma, ampulla of Vater, bile duct tumors) 5) chronic pancreatitis 6) prosthesis or stents in the common bile duct
Signs and Symptoms
1) Charcot’s triad – right upper quadrant pain, fever, jaundice 2) Reynolds’ pentad – right upper quadrant pain, fever, jaundice, hypotension, and mental status changes (delirium, anxiety, and coma) 3) nausea and/or vomiting 4) right upper quadrant tenderness (mild to moderate)
Characteristic Test Findings
Laboratory – 1) increased white blood cell count 2) increased serum bilirubin 3) increased transaminases (AST and ALT) Radiology – 4) dilated common bile duct (> 8mm)
Histology/Gross Pathology
1) most common infecting organism in developed nations is E. Coli 2) other causative gram-negative organisms – Enterococcus, Klebsiella 3) causative anaerobes – Bacteroides, Clostridium 4) gram-positive organism – Streptococcus faecalis 5) causative organisms occurring in Far East – Clonorchis, Ascaris
Associated Conditions
1) causes 50% of known liver abscesses 2) renal failure (ominous prognosis)
Inheritance/Epidemiology
can occur secondary to common bile duct stones after cholecystectomy – from a missed retained stone or the formation of a primary stone (almost always calcium bilirubinate)
Treatment
1) antibiotics (ampicillin-sulbactam, second- or third-generation cephalosporin, metronidazole, Zosyn 2) prompt mechanical decompression (surgery, stenting, spincterotomy) 3) removal of infected indwelling prosthesis 4) if stent is chronically indwelling, prophylactic change every 3 months is required
Tips for USMLE
1) Charcot’s triad occurs in only 50-60% of patients 2) Reynold’s pentad occurs in 20% of cases
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