title: The effects of retroperitoneal carbon dioxide insufflation on hemodynamics and arterial carbon dioxide.
abstract: BACKGROUND
  Laparoscopic techniques are being increasingly used for retroperitoneal surgery. However, hemodynamic and ventilatory efforts of retroperitoneal carbon dioxide (CO2) insufflation have not been studied. We hypothesized that differences in absorptive surface, anatomy, and compartment compliance could result in different hemodynamic and ventilatory effects between retroperitoneal and intraperitoneal insufflation.
  
  
  METHODS
  Pigs (n = 7) were anesthetized and stabilized. The peritoneal cavity was incrementally insufflated with CO2 to a maximum pressure of 25 cm H2O and the gas released. Hemodynamics and arterial blood gas values were recorded initially, at each level of insufflation, and following the pneumoperitoneum release until baseline values were reached. This insufflation protocol was repeated in the retroperitoneum.
  
  
  RESULTS
  Mean arterial pressure (111 mm Hg, 95% confidence interval 99 to 156) and cardiac output (3.7 L/min, 2.8 to 5.2) did not change with increasing insufflation pressure of either intraperitoneum or retroperitoneum. PaCO2 was directly related to insufflation pressure in both spaces, increasing from 41.2 mm Hg (37.3 to 43.4) at baseline to 57.7 mm Hg (47.6 to 82.1) at insufflation pressure of 25 cm H2O. After release of the insufflation gas, time to return to baseline PaCO2 was slightly less from the retroperitoneal space (73 minutes, 45 to 105) than the intraperitoneal (107 minutes, 35 to 175).
  
  
  CONCLUSIONS
  The effects of CO2 insufflation on hemodynamics and PaCO2 are the same in the retroperitoneal and intraperitoneal spaces.
authors: Department of Surgery, St. Paul's Hospital Pulmonary Research Laboratory, and University of British Columbia, Vancouver, Canada.
authors: J E
authors: JE
authors: Baird
authors: R
authors: R
authors: Granger
authors: R
authors: R
authors: Klein
authors: C B
authors: CB
authors: Warriner
authors: P T
authors: PT
authors: Phang
mesh_terms: D000818:Animals; D001784:Blood Gas Analysis; D002245:Carbon Dioxide / Q000097:blood* / Q000494:pharmacology*; D006439:Hemodynamics / Q000187:drug effects*; D011028:Pneumoperitoneum, Artificial; D012187:Retroperitoneal Space; D013552:Swine
chemical_list: D002245:Carbon Dioxide