[Risk factors and infection characteristics of secondary pancreatic infection in severe acute pancreatitis]

To explore risk factors and infection characteristics of secondary pancreatic infection in severe acute pancreatitis (SAP).

A clinical data of 49 patients with secondary pancreatic infection in severe acute pancreatitis (SPI group)were matched with 49 patients without infection in severe acute pancreatitis (NSPI group) between January 2003 and December 2005. The two groups were analyzed by a case-control study. Conditional Logistic regression model univariate and multivariate were used to screen out risk factors. The types of infection, the peak infection and the bacteria spectrum were analyzed in SPI group.

(1) In univariate Logistic regression analysis, 7 factors including continuous hypoalbuminemia, prolonged time of central venous catheter, usage of hormone, high APACHE II scores, multi-antibiotics, intestine dysfunction and continuous hyperglycemia were selected out. Moreover, the first three were statistically significant in multivariate Logistic regression analysis. (2) Pancreatic abscess ranked first in SPI group. Of all the pancreatic infection, 22.5% occurred within two weeks and 71.4% occurred in the 4th week or later. (3) In SPI group, 81 strains of microorganisms were cultured, including 45 strains of gram-negative bacteria (55.6%), 22 strains of gram-positive bacteria (27.2%), and 14 strains of fungi (17.3%). The common gram-negative bacteria were Escherichia coli, and the common gram-positive bacteria were Staphylococci and Enterococci. The fungi included Monilia and Yeastoid fungus. Further study revealed that 35 strains of all the microorganisms were intestinal bacteria (43.2%).

Continuous hypoalbuminemia, prolonged time of central venous catheter and usage of hormone were independent risk factors of SPI. The main type of infection was pancreatic abscess. Gram-negative bacteria, were the common bacteria causing secondary pancreatic infection.