The Comparison of the Oxidative Stress Effects of Different Gases and Intra-abdominal Pressures in an Experimental Rat Model

Abstract

Background: Laparoscopy is used for almost all types of abdominal surgery because of its advantages, which include shorter postoperative hospital stay. However, pneumoperitoneum used to facilitate the visual field has severe metabolic, hemodynamic, and inflammatory consequences depending on the pressure level and the gas used. Helium (He), an inert gas, has been recommended for establishment of pneumoperitoneum since it does not alter the blood pH and PCO₂. Yet the oxidative response after He insufflation remains unknown. This study was undertaken to compare the levels of free radical production and antioxidant status following He and CO₂ pneumoperitoneum at different intra-abdominal pressure values. Materials and methods: The subjects were 40 Spraque-Dawley male rats randomized to the following groups: He 10 (n = 8) was subjected to He pneumoperitoneum at 10 mm Hg for 60 minutes; He 15 (n = 8) was subjected to He pneumoperitoneum at 15 mm Hg for 60 minutes; CO₂ 10 (n = 8) was subjected to CO₂ pneumoperitoneum at 10 mm Hg for 60 minutes; CO₂ 15 (n = 8) was subjected to CO₂ pneumoperitoneum at 15 mm Hg for 60 minutes; and Control (n = 8) was subjected to sham operation without pneumoperitoneum. At the end of the experiment blood samples were obtained and plasma malondialdehyde, carbonyl, and sulphydryl levels were measured. Results: CO₂ pneumoperitoneum produced higher malondialdehyde and carbonyl responses and sulphydryl consumption compared to He, especially at 15 mm Hg (P = 0.01, P = 0.01, and P = 0.059, respectively). Conclusion: Helium seems to limit the postoperative oxidative response following laparoscopy.