Hemodynamic effects of the laparoscopic pneumoperitoneum during sepsis in a porcine endotoxic shock model

Objective The authors compared the hemodynamic effects of laparoscopic intervention with conventional laparotomy in an endotoxic shock model in the pig. Summary Background Data Laparoscopic techniques are being applied more frequently to severely ill patients to evaluate potential abdominal sources of sepsis. Although hemodynamic effects of laparoscopy are minimal in healthy patients, recent studies have shown more significant changes in patients with chronic cardiopulmonary disease. It is unclear whether these effects are applicable to acutely septic patients. Methods Twelve domestic pigs received intravenous lipopolysaccharide (LPS) injection and underwent surgical abdominal exploration using either laparoscopy or conventional laparotomy. For baseline comparison, four pigs underwent exploratory laparoscopy without intravenous LPS injection. Hemodynamic measurements and blood gas analyses were obtained using Swan-Ganz and arterial catheters. Results After LPS exposure, animals undergoing laparoscopic evaluation were significantly more hypercarbic (p < 0.01) and acidotic (p ( 0.01) than those undergoing conventional laparotomy. Their mean pulmonary arterial pressure and pulmonary vascular resistance were greater as well (not significant). The cardiac index (p < 0.05) and stroke volume (p < 0.05) were decreased in the laparoscopic group. Their oxygen delivery was decreased and oxygen consumption increased, although these were not significantly different from those of the laparotomy group. The degree of acidosis was highly correlated with the cardiac index (correlation coefficient, r = 0.82). Conclusions Animals exposed to LPS tolerate laparoscopy but with significant hemodynamic compromise. Much of this effect seems to be mediated by a cardiodepressive effect of acidosis. This study suggests that laparoscopic intervention, when used in septic patients, should be used with caution.