Evaluation of the effects of a pneumoperitoneum with carbon dioxide or helium in a porcine model of endotoxemia

Background: The expansion of the laparoscopic techniques to the critically ill patient is currently under debate. In order to evaluate the potential r isks of performing laparoscopy in a body with signs of sepsis, the effects of the pneumoperitoneum were studied in a porcine model of mild endotoxemia . Methods: Twenty-eight pigs were separated into four groups of seven anima ls: untreated control (C), 2 mu g/kg/h endotoxin (E), endotoxin and a pneum operitoneum (3 h, 15 mmHg) with CO2 (EC) or with helium (EH). Hemodynamic a nd homeostatic variables were studied for a period of 5.5 h. Primary endpoi nts were arterial and mucosal pH and the ATP content of the bowel wall. Sta tistical evaluation was performed using analysis of variance and the Bonfer roni test. Results: Endotoxin infusion induced characteristic symptoms of e arly sepsis: increase of arterial CO2, pulmonary arterial, portal venous, a nd pulmonary artery wedge pressure, and decrease of arterial pressure, card iac output, arterial and mucosal pH. An additional pneumoperitoneum led to aggravation of all criteria with significant alterations in arterial and mu cosal pH, arterial CO2, wedge and portal venous pressure. The most striking derangement of mean values was observed for mucosal pH (EC: 7.40, EH: 7.54 ) and arterial pH (EC: 7.15, EH: 7.18). In group EC, two animals died in se ptic shock. Conclusion: Applying a pneumoperitoneum during an ongoing sepsi s significantly deteriorates hemodynamic and homeostatic variables, thus en hancing the risk of severe complications.