Effects of Carbon Dioxide Pneumoperitoneum on the Inflammatory Response and Bacterial Translocation in Intraabdominal Infection

Background: This study evaluated the effect of CO2 pneumoperitoneum on intraabdominal infection and bacterial translocation in intraabdominal infection. Materials and Methods: Escherichia coli and Bacteroides fragilis were injected separately into the abdominal cavities of 30 New Zealand white rabbits to establish two animal models of intraabdominal infection. Each model was divided into a laparotomy group, a pneumoperitoneum group, and a control group. Before and 1, 2, 4, and 7 days after surgery, blood and peritoneal fluids were obtained to determine bacterial culture and serum interleukin-6, tumor necrosis factor-alpha, and C-reactive protein levels by enzyme-linked immunosorbent assay. The total number of white blood cells (WBCs) was measured. Seven days after surgery, the animals were sacrificed and dissected, and liver, kidney, and spleen tissues were obtained for bacterial culture. Results: In the two bacterial models, incidence rates of bacteremia were higher in the laparotomy and pneumoperitoneum groups than in the control group. However, there were no significant differences between the laparotomy and pneumoperitoneum groups. Visceral bacterial translocation was detected in each group with no significant difference among the three groups. The change of inflammatory factors in the E. coli group and the B. fragilis group was nearly the same: the inflammatory factor levels and WBC counts in the laparotomy group were significantly higher than in the pneumoperitoneum group. The inflammatory factor levels and WBC counts in the pneumoperitoneum group increased slowly and were restored to normal quickly. Conclusions: In the intraabdominal infection animal model of the pneumoperitoneum group, the inflammatory response was weaker and the immune function was less affected and restored to normal more quickly than in the laparotomy group. The incidence rate of visceral bacterial translocation was not higher than that in the laparotomy group.