CO2 pneumoperitoneum impact on early liver and lung cytokine expression in a rat model of abdominal sepsis
OBJECTIVE To analyze the effect of CO2 pneumoperitoneum on the inflammatory response induced by sepsis during laparoscopy. SUMMARY BACKGROUND DATA A growing body of evidence challenges the once generally accepted notion that smaller incisions alone account for the observed benefits of the laparoscopic approach. Furthermore, laparoscopic surgery is now being applied to a broad spectrum of patients, including those in whom the inflammatory response is ignited. Delineation of the effects of CO2 pneumoperitoneum on the inflammatory response induced by sepsis is needed. METHODS Sepsis was induced in rats by cecal ligation and puncture (CLP) performed either open or laparoscopically using CO2 or helium as insufflation gases. Animals were killed 24 hours postoperatively, at which time whole blood was collected for complete blood cell counts and livers were harvested for analysis of hepatic expression of the rat acute phase genes alpha2-macroglobulin and beta-fibrinogen. RESULTS Laparoscopic CLP using CO2 resulted in significantly reduced hepatic expression of the rat acute phase gene alpha2-macroglobulin compared to both laparoscopic CLP using helium and open CLP. Hepatic expression of another rat acute phase gene, beta-fibrinogen, paralleled that of alpha2-macroglobulin and was significantly reduced following laparoscopic CLP using CO2 compared to laparoscopic CLP using helium. Total white blood cell and neutrophil counts following CLP were both significantly higher when CLP was performed laparoscopically using CO2 than when CLP was performed open or laparoscopically using helium. CONCLUSIONS Intra-abdominal CO2 present during laparoscopy attenuates the acute phase inflammatory response associated with perioperative sepsis.