The purpose of this study was to investigate whether an intra-abdominal pressure (IAP) of 30 mmHg lasting 24 h in a porcine model will lead to a condition comparable with the abdominal compartment syndrome (ACS) in humans. We examined 12 intubated and anesthetized domestic pigs with a mean body weight of 52.5 +/- 4.9 kg. Using a CO2 pneumoperitoneum, the IAP was increased to 30 mmHg (study group, n = 6) for an investigation period of 24 h. In the control group, the IAP remained unchanged. Investigated parameters were cardiac output (CO), peak inspiratory pressure (PIP), urine output (UO), as well as serum alanine aminotransferase (ALT), lactate, lipase, and alkaline phosphatase (AP). Additionally, histopathological examinations were performed. In the study group, CO was significantly reduced compared with the control group. All animals of this group became anuric and their PIP exceeded 40 cm H2O. Furthermore, ALT, AP, lipase, and lactate were significantly increased. Histopathologically, high-grade atelectasis in the lower lobes of the lung together with medium grade liver necrosis, medium grade proximal tubular epithelial necrosis, and medium grade mucosal bowel damage were observed. In this porcine model, an intra-abdominal pressure of 30 mmHg led to a condition comparable with the ACS. Because function or integrity of additional organ systems was impaired, an IAP of 30 mmHg has to be considered a predisposition for the multi-organ dysfunction syndrome in this porcine model.

In our surgical intensive care unit population, the estimation of EVLW by transpulmonary thermodilution was influenced by the amount of EVLW, the Pao2/Fio2 ratio, the tidal volume, and the level of positive end-expiratory pressure. However, compared with the double indicator method, transpulmonary thermodilution estimation remained clinically acceptable even in patients with severe lung disease.