title: Hemodynamic and tissue blood flow responses to long-term pneumoperitoneum and hypercapnia in the pig.
abstract: BACKGROUND
  Increased peritoneal blood flow may influence the ability of cancer cells to adhere to and survive on the peritoneal surface during and after laparoscopic cancer surgery. Carbon dioxide (CO2) pneumoperitoneum is associated with a marked blood flow increase in the peritoneum. However, it is not clear whether the vasodilatory effect in the peritoneum is related to a local or systemic effect of CO2.
  
  
  METHODS
  In this study, 21 pigs were exposed to pneumoperitoneum produced with either CO2 (n = 7) or helium (He) (n = 7) insufflation at 10 mmHg for 4 h, or to two consecutive levels of hypercapnia (7 and 11 kPa) (n = 7) produced by the addition of CO2 to the inhalational gas mixture. Tissue blood flow measurements were performed using the colored microsphere technique.
  
  
  RESULTS
  Blood flow in peritoneal tissue increased during CO2, but not He, pneumoperitoneum, whereas it did not change at any level of hypercapnia alone. There was no change in blood flow in most organs at the partial pressure of CO2 (PaCO2) level of 7 kPa. However, at a PaCO2 of 11 kPa, blood flow was increased in the central nervous system, myocardium, and some gastrointestinal organs. The blood flow decreased markedly in all striated muscular tissues during both levels of hypercapnia.
  
  
  CONCLUSIONS
  The effect of CO2 on peritoneal blood flow during laparoscopic surgery is a local effect, and not attributable to central hemodynamic effects of CO2 pneumoperitoneum or high systemic levels of CO2.
authors.affiliation: National Center for Advanced Laparoscopic Surgery, St. Olav University Hospital, Norwegian University of Science and Technology, N-7006, Trondheim, Norway.
authors.forename: Y
authors.initials: Y
authors.lastname: Yavuz
authors.forename: K
authors.initials: K
authors.lastname: Rønning
authors.forename: K
authors.initials: K
authors.lastname: Bakkelund
authors.forename: O
authors.initials: O
authors.lastname: Lyng
authors.forename: P
authors.initials: P
authors.lastname: Aadahl
authors.forename: R
authors.initials: R
authors.lastname: Mårvik
authors.forename: J E
authors.initials: JE
authors.lastname: Grønbech
mesh_terms: D000818:Animals; D002245:Carbon Dioxide / Q000097:blood; D002490:Central Nervous System / Q000098:blood supply; D003326:Coronary Circulation; D005260:Female; D041981:Gastrointestinal Tract / Q000098:blood supply; D006371:Helium; D006439:Hemodynamics; D006935:Hypercapnia / Q000097:blood / Q000503:physiopathology*; D008297:Male; D018482:Muscle, Skeletal / Q000098:blood supply; D010313:Partial Pressure; D010537:Peritoneum / Q000098:blood supply*; D011028:Pneumoperitoneum, Artificial; D012039:Regional Blood Flow; D013552:Swine; D013997:Time Factors
chemical_list: D002245:Carbon Dioxide; D006371:Helium