The effect of warm humidified CO2 on the dissipation of residual gas following laparoscopy in piglets.

Study Objective: To determine whether residual gas volume reduces more quickly after insufflation with humidified CO(2) compared with dry CO(2).

Design: Animal study (Canadian Task Force classification I).

Setting: University.

Intervention: Piglets were randomly divided into two groups of five and underwent abdominal insufflation with either cold, dry CO(2) or warm, humidified CO(2).

Measurements And Main Results: Following insufflation, anteroposterior and lateral gas-bubble radiographic images were obtained at 5, 15, 30, 45, and 60 minutes, and the area of each gas-bubble profile calculated. Blood samples were obtained at 0, 2, 4, and 5 hours, and they were analyzed for IL-1beta and TNFalpha. Peritoneal tissue samples were obtained on euthanasia at 5 hours for histological analysis. The results indicate that following pneumoperitoneum, residual CO(2) dissipates more rapidly when the gas is heated and humidified compared with when it is cool and dry. This is associated with a reduction in the duration of the inflammatory response as measured by TNF alpha production, although no histologic differences in the peritoneal tissue were observed.

Conclusion: Heating and humidifying CO(2) leads to faster dissipation of residual gas associated with a reduced duration of inflammation, which may contribute toward a reduction in postlaparoscopic pain.