title: The effect of warm humidified CO2 on the dissipation of residual gas following laparoscopy in piglets.
abstract: OBJECTIVE
  To determine whether residual gas volume reduces more quickly after insufflation with humidified CO(2) compared with dry CO(2).
  
  
  METHODS
  Animal study (Canadian Task Force classification I).
  
  
  METHODS
  University.
  
  
  METHODS
  Piglets were randomly divided into two groups of five and underwent abdominal insufflation with either cold, dry CO(2) or warm, humidified CO(2).
  
  
  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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Anesthesia, University of Otago, Dunedin, New Zealand.
authors.forename: Peter A
authors.initials: PA
authors.lastname: Glew
authors.forename: Matthys J J
authors.initials: MJ
authors.lastname: Campher
authors.forename: Kay
authors.initials: K
authors.lastname: Pearson
authors.forename: John C
authors.initials: JC
authors.lastname: Schofield
authors.forename: Andrew K
authors.initials: AK
authors.lastname: Davey
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002245:Carbon Dioxide / Q000494:pharmacology*; D016207:Cytokines / Q000032:analysis / Q000378:metabolism; D004867:Equipment Design; D006358:Hot Temperature; D006813:Humidity; D018836:Inflammation Mediators / Q000032:analysis; D007327:Insufflation / Q000009:adverse effects / Q000379:methods*; D010535:Laparoscopy / Q000009:adverse effects / Q000379:methods*; D023421:Models, Animal; D010149:Postoperative Pain / Q000517:prevention & control; D011028:Pneumoperitoneum, Artificial / Q000009:adverse effects / Q000379:methods; D011897:Random Allocation; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013552:Swine; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism
chemical_list: D016207:Cytokines; D018836:Inflammation Mediators; D014409:Tumor Necrosis Factor-alpha; D002245:Carbon Dioxide