BILIARY TRACT INFECTION

Infection of the gallbladder (cholecystitis) may be acute or chronic, or the two types may coexist. In more than 90% of cases, stones are present in the cystic duct. Common clinical findings include pain in the right upper quadrant of the abdomen, fever, jaundice and a palpable gallbladder. Ultrasonography and hepatobiliary radionuclide scanning with an acetanilide iminodiacetic acid (IDA) derivative are both rapid and sensitive techniques for diagnosing this disease. The causative bacteria are most commonly E. coli and other organisms of the family Enterobacteriaceae and streptococci. Anaerobic bacteria are found occasionally, but seem to be involved less frequently than in most other types of intra-abdominal infection.

In acute cholecystitis and there is an intense acute inflammatory reaction which may involve the full thickness of the gallbladder wall and may progress to transmural necrosis and perforation. In emphysematous cholecystitis, a severe form occurring primarily in diabetics, gas may be seen within the lumen and wall of the gallbladder . In chronic cholecystitis, the wall of the gallbladder may be markedly thickened; multiple stones may be present inside the gallbladder, and chronic inflammatory changes and fibrosis may be appa-rent in the wall and on the serosal surface .

Most cases of acute cholecystitis resolve within a few days, but elderly or seriously ill patients, or those who develop complications such as perforation or gangrenous (emphysematous) cholecystitis, should be treated with antibiotics effective against Gram-negative bacilli and anaerobic bacteria, e.g. piperacillin, mezlocillin, or a combination of an aminoglycoside plus metronidazole or clindamycin. Immediate surgical intervention (cholecystectomy or cholecystectomy with drainage) is required for perforation, pericholecystic abscess or gangrenous cholecystitis. Acute cholecystitis is often associated with extension of infection into the extrahepatic and intrahepatic biliary system (ascending cholangitis) . The cholangitis may become complicated by multiple intrahepatic abscesses .

Ascending cholangitis usually produces severe systemic illness with high fever and chills, jaundice and severe pain and tenderness over the liver. ēCharcot's triad' (fever, chills and jaundice) is present in 85% of cases. Ascending cholangitis is frequently associated with bacteraemia; the organisms isolated most commonly are E. coli, Bacteroides fragilis and Clostridium perfringens. Prompt therapy with appropriate antibiotics administered intravenously and relief of biliary obstruction is required. The technique of endoscopic retrograde cholangio-pancreatography (ERCP) has revolutionized the diagnosis and treatment of this condition by allowing direct visualization of gallstones in the common bile duct

Either sphincterotomy with stone extraction or non-operative decompression of the biliary system by placement of an indwelling stent may be employed to relieve the obstruction.