Risk Factors of Wound Infection in Biliary Surgery: A prospective study

Kim, Young Woo; Han, Ho Seong; Lee, Ryoung Ah; Choi, Yong Man; Kim, Ok Young

Abstract

BACKGROUND: Lowering the wound infection rate is very important to decrease morbidity, mortality, and the cost of therapy. We wanted to know the bacteriologic pathogen of surgical infection, to verify the role and proper selection of prophylactic antibiotics, and to figure out the risk factors of surgical infection in the biliary area.
METHODS
A prospective study was done for 109 patients who underwent biliary operations, excluding laparoscopic cholecystectomy from Mar. 1997 to Feb. 1998. Bacteriologic data were collected from 96 patients among them. Wound infection was defined as a purulent discharge from the wound. Ordinary bacterial cultures were taken from the peritoneal cavity (liver bed) and the wound subcutaneous area. Items of investigations were age, sex, degree of obesity, operation time, ASA classification, incision, suture materials, transfusion, used antibiotics, serum albumin, serum glucose, and hemoglobin. Statistical analysis were done with the Mann-Whitney-Wilcoxon-rank test, the Students t-test, the Chi-square test, and Fishers exact test.
RESULTS
Wound infections occurred in 5 cases (4.8%). Culture positivity from the wounds was 38.5% (37/96), and that than the peritoneal cavity were 40.6% (39/96). The bacteria isolated from the peritoneal cavity were mainly gram-negative rods (E. coli, Klebsiella, Enterobacter, Pseudomonas, Serratiae, Morganella); gram-positive cocci were also isolated (Enterococcus, Streptococcus). The most common bacteria isolated from the wound was gram-positive Enterococcus; gram-negative rods were also common (Klebsiella, E. coli, Enterobacter). Of the investigated risk factors, a positive culture and biliary tract infection were statistically significant risk factors of wound infection (p<0.05).
CONCLUSION
Taking a bacterial culture from the wound and from the peritoneal cavity is important because it directly correlates with the degree of contamination and defines a high risk of infection. Prophylactic antibiotic administration with 3rd generation cephalosporin and aminoglycoside is justified in view of the organisms isolated from the culture.