The effect of experimentally induced carbon dioxide pneumoperitoneum on intra-abdominal and intra-esophageal pH

Abstract

Aim: An experimental study was performed to evaluate the effect of CO2 pneumoperitoneum on intra-abdominal (IA) and intra-esophageal (IE) pH. Material and methods: The study included 18 Wistar rats. In the control group (n = 6) a pH catheter was inserted into the peritoneal cavity via a left upper quadrant incision and another catheter was inserted into the lower esophagus via the oral route. Pre- and post-insufflation IA and IE pH were recorded every 5 min for 1 h. In the experimental groups, in addition to pH catheters, a 16-G catheter was inserted into the abdomen above the umbilicus. In the O-2 group (n = 6) 95% O-2 and 5% CO2 were insufflated with a pressure of 10 mmHg. In the CO2 group (n = 6), CO2 was insufflated with the same pressure and duration. Results: In the CO2 group, IA and IE pH values significantly decreased (P < 0.05). IA pH values decreased in the CO2 group when compared to the control and O-2 groups (P < 0.05). There was not a significant difference in IE pH between the CO2 group and the other groups. Conclusion: CO2 insufflation decreased IA pH values. Decreased pH values obtained with continuous recordings of the esophagus may have been related to increases in intra-abdominal pressure, rather than the metabolic effects of CO2 pneumoperitoneum.