Effects of laparoscopic vs laparotomy treatment of E-coli peritonitis on hemodynamic responses in a porcine model

Background: Laparoscopic surgery is being used now for increasingly diverse clinical applications, including diagnosis and treatment of appendicitis a nd bacterial peritonitis. However, some concerns and controversies exist re garding the effectiveness of laparoscopic irrigation of the abdominal cavit y compared with that achieved during laparotomy. Of no less importance is c oncern that establishing a CO2 pneumoperitoneum in patients with cardiopulm onary insufficiency or endotoxemic shock may compromise hemodynamic functio n. The objective of this randomized, controlled study was to determine the effects of laparoscopic versus laparotomy intervention on hemodynamic and o utcome measurements using a porcine model of Escherichia coli peritonitis. Methods: For this study, 24 specific pathogen-free Hanford pigs underwent s urgical placement of carotid, Swan-Ganz, and peritoneal catheters. After a 24-h recovery period, one subset of pigs (n = 12) received a bolus infusion of 9 x 10(8) CFU/kg E. coil intraperitoneally (septic) and intravenous flu id resuscitation. The remaining 12 pigs were not challenged with E. coli (c ontrol). Twenty-four hours later, all 24 pigs underwent either laparoscopic or open peritoneal irrigation with saline, then were reevaluated 48 h afte r surgical intervention. Standard cardiopulmonary, hematologic, and bacteri ologic assessments were obtained both perioperatively and 48 h after surgic al intervention. Results: Pigs given E. coli exhibited significantly elevated heart rates an d core temperatures and decreased O-2 saturation during the initial 6 h. Wi thin 24 h, these pigs exhibited respiratory alkalosis, altered blood leukoc yte profiles, and E. coli-infected peritoneal fluid. Random blood samples f rom the septic pigs tested negative for E. coli. Mean pulmonary artery and capillary wedge pressures were lower (p < 0.05) in septic than in control p igs before and after surgical intervention. Septic pigs that underwent lapa roscopy had significantly lower (p < 0.05) arterial pH and higher arterial pCO(2) levels than septic pigs after laparotomy. Other cardiopulmonary resp onses were similar irrespective of the surgical modality used. One of six s eptic pigs from each surgical group still had a coli growth in its peritone al fluid 48 h after surgical intervention. Conclusion: Laparoscopic intervention demonstrated effectiveness equal to t hat of laparotomy for treating acute E. coli peritonitis in pigs without se ptic shock.