Increased intra-abdominal pressure causes bacterial translocation in rabbits

Abdominal compartment syndrome (ACS) is defined as intra-abdominal hypertension associated with organ dysfunction. Subsequently, increased intra-abdominal pressure (IAP) adversely affects the pulmonary, cardiovascular, renal, musculoskeletal/integumentary and central nervous systems. Bacterial translocation (BT), which is defined as the movement of viable enteric bacteria to the mesenteric lymph nodes, liver and spleen, occurs after various types of stress and results in splanchnic ischemia. In this experimental study, we aimed to investigate the effects of various levels of increased IAP on BT in rabbits; IAP was increased by the intra-abdominal balloon-insufflation method, thus simulating noncompliant abdominal-wall closure under tension.

Fifty rabbits were randomly assigned to 1 of 5 groups, with each group comprising 10 animals. In group I (control group), an intra-abdominal balloon was placed without inflation. In groups II, III, IV and V, IAPs of 10, 15, 20 and 25 mmHg, respectively, were established via inflation of the intra-abdominal balloon. All groups underwent laparotomy after 12 hours. Multiple biopsies were taken from ileocecal lymph nodes, the spleen and liver.

BT was observed to some degree in all 4 experimental groups. A gradual increase in the phenomenon was noted as IAP increased from 10 to 15 mmHg; and BT was overt at 20 mmHg, and significant at 25 mmHg. Klebsiella pneumoniae, Serratia marcescens, and Escherichia coil were the predominant pathogens identified by culture.

We propose that an intravesical pressure (IVP) of 15 mmHg is the critical point for BT in patients with increased IAP. In this experimental study, BT occurred when IVP reached 20 mmHg. We suggest that IVP monitoring is desirable in the management of patients with ACS, and that decompressive laparotomy should be performed in patients with IVP >20 mmHg.