Objective: To investigate the effects of pneumoperitoneum with carbon dioxide on metabolism in pigs with endotoxemia. Methods: Twenty-one pigs randomly divided into three groups: control group(group A)

endotoxin group (group B

2μg/kg·h)

endotoxin and pneumoperitoneum with CO2 group (group C

15mmHg). The experimental period of the study was 5.5 hours ( 30 min endotoxemia

3 hours pneumoperitoneum

2 hours further monitor). Primary endpoints were arterial blood gas

mucosal pH of jejunum(ipH) and ATP level of jejunum wall. Statistical evaluation was performed by analysis of ANOVA Student-Newman-Keuls. Results: Endotoxin infusion can induce symptoms of an early septic shock. Two animals in group C died in 1~2 hours after pneumoperitoneum with CO2 due to serious acidosis and shock. Pneumoperitoneum with CO2 led to significant decrease of apH

ipH

aHCO3 - and aBE and significant increase of aPCO2. Endotoxin may induce significant increase of plasma TNF-α

but there was no difference between group B and group C. ATP level of jejunum wall in group C was lower than that of group A and group B

but there was no significant diffrence in all of the three groups. Conclusion: Our study suggests that pneumoperitoneum with carbon dioxide during endotoxemia can seriously damage the acid-base balance and metabolism of energy of experimental animal. We think laparoscopic operation with pneumoperitoneum with CO2 can enhance the risk of patients with sepsis.