Cardiopulmonary effects of the laparoscopic pneumoperitoneum in a porcine model of adult respiratory distress syndrome

Background: Increasingly, laparoscopy is being used in critically ill patients in whom there is a question of intra-abdominal sepsis. We examine the cardiopulmonary effects of laparoscopy in a porcine model of adult respiratory distress syndrome (ARDS). Methods: Domestic pigs (n = 12) underwent saline lung lavage and subsequent surgical abdominal exploration using either laparoscopy or conventional laparotomy. Hemodynamic and respiratory measurements were obtained. Results: After pulmonary lavage, the two groups developed similarly diminished arterial pO2 (P <0.001), a worsened pulmonary shunt (P <0.001), and an increased alveolar-arterial oxygen gradient (P <0.001). The pulmonary compliance was significantly decreased in the animals undergoing laparoscopy (versus laparotomy, P <0.05). The mean pulmonary arterial pressure did not differ between the groups. The laparoscopic group had a higher pCO2 (not significant) and was more acidotic (P <0.05) than the laparotomy group. The laparoscopic animals had an increased heart rate (P <0.05), cardiac index (P <0.01), and oxygen delivery (P <0.005) as compared with the laparotomy group. Conclusions: During laparoscopy, animals with ARDS demonstrate further compromise in pulmonary physiologic parameters but overall cardio-respiratory function is preserved.