Background Trauma, vascular lesions or peritonitis can cause an increase of the intra-abdominal pressure (IAP) or an abdominal compartment syndrome (ACS). Maintaining the cardiac output (CO) cannot prevent impairment of organ function. However, it is unknown, whether an IAP of 30 mmHg can lead to oragn damage within 6 an 12 h despite unchanged CO.

Methods We examined 16 male pigs (50 kg, SD 1,8). Animals were ventilated volume controlled and analogue-sedated using ketamine and pentobarbital. Via CO2-pneumoperitoneum, IAD was increased to 30 mmHg for 6 and 12 h (each n = 6). In the control (n = 4) the IAP remained unchanged. Heartrate (HR), mean arterial pressure (MAP), central venous pressure (CVP), CO and peak inspiratory pressure (PIP) were continuously recorded. Additional to basic fluid replacement (2 ml/kg/h) crystalloid volume was given whenever continuously monitored CO was below control values. In the end, animals were given an overdose of pentobarbital and specimen were taken from lung, heart, kidney, liver stomach as well as small and large bowel. Damage of bowel specimen was classified according to Park whereas damage to other organs was classified as none, low, intermediate and high. Statistic analysis was performed using ANOVA and post-hoc analysis together with paired tests. A p < 0,05 was considered significant and was adjusted (Bonferroni) when multiple paired testing was performed.

Results A significant increase of CVP and PIP was found whereas the other haemodynamic data was not changed. Compared to control, an increased morphologic damage was found in lung, stomach (12 h), liver, bowel and kidney. The myocardium was statistically unchanged.

Conclusion Even a short-termed increase of the IAP for 6 h results in morphologic organ impairment despite an unchanged CO. In the clinical regard, these results imply an immediate decompression in the presence of a critically increased IAP.