title: Carbon dioxide pneumoperitoneum causes severe peritoneal acidosis, unaltered by heating, humidification, or bicarbonate in a porcine model.
abstract: BACKGROUND
  Carbon dioxide (CO(2)) is the most common gas used for insufflation in laparoscopy, but its effects on peritoneal physiology are poorly understood. This study looks at the changes in peritoneal and bowel serosal pH during CO(2) pneumoperitoneum, and whether heating and humidification with or without bicarbonate alters the outcomes.
  
  
  METHODS
  Twenty-one pigs divided into four groups as follows: (1) standard (STD) laparoscopy (n = 5); (2) heated and humidified (HH) laparoscopy (n = 6); (3) heated and humidified with bicarbonate (HHBI) laparoscopy (n = 5); and (4) laparotomy (n = 5). Peritoneal pH, bowel serosal pH, and arterial blood gas (ABG) were obtained at 15-min intervals for 3 h.
  
  
  RESULTS
  Severe peritoneal acidosis (pH range 6.59-6.74) was observed in all laparoscopy groups, and this was unaltered by heating and humidification or the addition of bicarbonate. Bowel serosal acidosis was observed in all laparoscopy groups with onset of pneumoperitoneum, but it recovered after 45 minutes. No significant changes in peritoneal or bowel serosal pH were observed in the laparotomy group.
  
  
  CONCLUSIONS
  CO(2) pneumoperitoneum resulted in severe peritoneal acidosis that was unaltered by heating and humidification with or without bicarbonate. Alteration in peritoneal pH may conceivably be responsible for providing an environment favorable for tumor-cell implantation during laparoscopy.
authors.affiliation: Department of General Surgery, Lahey Clinic Medical Center, 41 Mall Road, Burlington, MA 01805, USA. yewtohwong@hotmail.com
authors.forename: Y T
authors.initials: YT
authors.lastname: Wong
authors.forename: P C
authors.initials: PC
authors.lastname: Shah
authors.forename: D H
authors.initials: DH
authors.lastname: Birkett
authors.forename: D M
authors.initials: DM
authors.lastname: Brams
mesh_terms: D000138:Acidosis / Q000139:chemically induced*; D000818:Animals; D001639:Bicarbonates / Q000627:therapeutic use; D002245:Carbon Dioxide / Q000009:adverse effects*; D004195:Disease Models, Animal; D006358:Hot Temperature / Q000627:therapeutic use; D006813:Humidity; D010532:Peritoneal Diseases / Q000139:chemically induced*; D011028:Pneumoperitoneum, Artificial / Q000379:methods*; D012720:Severity of Illness Index; D013552:Swine; D017211:Treatment Failure
chemical_list: D001639:Bicarbonates; D002245:Carbon Dioxide