Biliary tract infection in patients with acute biliary pancreatitis.

Background: The presence of infective microorganisms in the bilio-pancreatic tract is believed to be important in both the onset and outcome of acute biliary pancreatitis. In this study, the characteristics of bile colonization or infection in human pancreatitis were investigated in order to optimize prophylactic antibiotic therapy.

Methods: In 174 patients, 22 clinical and biological factors were recorded prospectively on admission and compared with the bacteriological findings at the time of surgery.

Results: There was a significant difference between patients with negative or positive bile cultures in six parameters: Age (57.7 +/- 1.7 vs. 68.5 +/- 1.5 years, p < 0.001), serum concentrations of glucose (132 +/- 4 vs. 149 +/- 6 mg/dL, p < 0.02) and alanine aminotransferase (ALT) (304 +/- 28 vs. 226 +/- 25 IU/L, p < 0.05) and hematocrit (43.4 +/- 0.4% vs. 41.7 +/- 0.5%, p < 0.05), Glasgow pancreatitis score (1.58 +/- 0.11 vs. 1.97 +/- 0.10, p < 0.01) and APACHE II score (6.20 +/- 0.38 vs. 7.82 +/- 0.35, p < 0.005). The prediction of the presence of bacteria in bile by each of these individual parameters, however, was of variable accuracy. From 82 patients with positive bile cultures, a total of 150 microorganisms were isolated, including 66 gram-positive aerobes, 66 gram-negative facultative anaerobes, 15 obligate anaerobes, and three fungi. The most common organisms were Escherichia coli (20.6%), followed by enterococci (18%) and streptococci (15.3%).

Conclusion: Patients with acute biliary pancreatitis who manifest abnormalities of one or more of the above-mentioned risk factors are more likely to have positive bile cultures. Whether such patients might benefit from early antibiotic therapy directed against both gram-negative bacilli and gram-positive cocci needs to be determined.