The effect of gases in the intraperitoneal space on cytokine response and bacterial translocation in a rat model

Background: The aim of this study was to examine cytokine response and bact erial translocation after exposure of the intraperitoneal space to carbon d ioxide (CO2), helium (He), and air (Air) in a rat model. Methods: For this study, 120 Sprague-Dawley rats underwent anesthesia only (Control), 10 mmHg pneumoperitoneum (PP), or abdominal wall lift (AWL). The rats were divided into five groups according to experimental procedure: Co ntrol, PP-CO2, AWL-CO2, AWL-He, and AWL-Air. At 0, 3, 6, and 24 h after the procedures, the levels of interleukin 1 beta (IL-1 beta) and interleukin 6 (IL-6) in both plasma and peritoneal lavage fluid (PLF) were measured, and the translocation of bacteria to the mesenteric lymph nodes was evaluated. Results: The plasma IL-1 beta and IL-6 levels in the PP-CO2, AWL-CO2, and A WL-He groups were significantly lower than those in AWL-Air group at 6 h (p < 0.05). The PLF IL-1<beta> (at 3, 6, and 24 h) and IL-6 (at 6 h) levels i n the AWL-CO2 group were significantly lower than those in the AWL-Air grou p (p < 0.05). There were no significant differences in IL-1<beta> and IL-6 responses among the PP-CO2, AWL-CO2, and AWL-He groups. The AWL-CO2 and PP- CO2 groups had lower incidences of bacterial translocation than did the AWL -Air group (p < 0.05). Conclusions: The results from this study suggest that the gas in the intrap eritoneal space, but not the increased intraabdominal pressure, causes the alterations in host cytokine response and bacterial translocation. Carbon d ioxide may play a primary role in the reduced immune response associated wi th laparoscopic surgery.