title: Protective effect of carbon dioxide against bacterial peritonitis induced in rats.
abstract: BACKGROUND
  Carbon dioxide (CO(2)) has been used in the food industry as an antimicrobial agent. This study aimed to investigate whether CO(2) pneumoperitoneum might act similarly as an antimicrobial agent in the infected peritoneal cavity.
  
  
  METHODS
  Peritonitis was induced in 58 rats by intraabdominal injection of an Escherichia coli inoculum (6 x 105 colony-forming units [CFU]/ml). Control rats were injected with saline solution. The rats were randomly divided into four groups: rat control (RC, n = 15), bacterial inoculation control (BIC, n = 10), bacterial inoculation and laparotomy (BIL, n = 17), and bacterial inoculation and CO(2) pneumoperitoneum (BIP, n = 16). The survival rates and histopathologic changes in the abdominal wall muscles, spleen, liver, intestines, and omentum were evaluated, and the samples were classified as "preserved" or "inflamed" (acute inflammation or tissue regeneration).
  
  
  RESULTS
  The survival rates for the four groups were as follows: RC (100%), BIP (75%), BIL (53%), and BIC (30%). With regard to survival rates, statistically significant differences were observed between the following groups: RC and BIC (p = 0.0009), RC and BIL (p = 0.0045), BIP and BIC (p = 0.0332), and RC and BIP (p = 0.0470). No significant differences regarding survival rates were observed between the BIL and BIC groups or between the BIP and BIL groups. With regard to the number of inflamed samples per group, a statistically significant difference was observed between the BIC and RC groups and the BIL and RC groups (p = 0.05).
  
  
  CONCLUSIONS
  Carbon dioxide pneumoperitoneum has a protective effect against bacterial peritonitis induced in rats.
authors.affiliation: Departments of Surgical Gastroenterology and Experimental Surgery, São Paulo Hospital for State Civil Servants, São Paulo, Brazil. smcsorbello@uol.com.br
authors.forename: Albino Augusto
authors.initials: AA
authors.lastname: Sorbello
authors.forename: Joao Luiz Moreira Coutinho
authors.initials: JL
authors.lastname: Azevedo
authors.forename: Junko Takano
authors.initials: JT
authors.lastname: Osaka
authors.forename: Sueli
authors.initials: S
authors.lastname: Damy
authors.forename: Luiz Mattosinho
authors.initials: LM
authors.lastname: França
authors.forename: Erasmo Carlos
authors.initials: EC
authors.lastname: Tolosa
mesh_terms: D000818:Animals; D001424:Bacterial Infections / Q000517:prevention & control*; D002245:Carbon Dioxide / Q000627:therapeutic use*; D008297:Male; D010538:Peritonitis / Q000382:microbiology* / Q000517:prevention & control*; D011027:Pneumoperitoneum; D051381:Rats; D011916:Rats, Inbred F344
chemical_list: D002245:Carbon Dioxide