OBJECTIVETo assess the effect of decompression in different time on systemic hemodynamics and oxygen metabolism in a 24 h lasting porcine model of severe acute pancreatitis (SAP) incorporating intra-abdominal hypertension (IAH).

METHODSFollowing baseline registrations, SAP was induced in all 18 animals. A N(2) pneumoperitoneum was used to increase the intra-abdominal pressure (IAP) to 25 mmHg (1 mmHg = 0.133 kPa) in 12 of 18 SAP animals. After 6 hours, decompression was applied in 6 of these 12 pigs and the other 6 animals received decompression at 9 h since the induction of IAH. The investigation period was 24 h. Heart rate (HR), cardiac output (CO), central venous pressure (CVP), mean arterial pressure (MAP) and pulmonary arterial wedge pressure (PAWP) were continuously recorded with the aid of Swan-Ganz catheter and electrocardiography monitor; Oxygen partial pressure of artery (PaO(2)), carbon dioxide partial pressure of artery (PaCO(2)) and central venous oxygen saturation (ScvO(2)) were measured by blood-gas analysis. Besides that, systemic oxygen delivery (DO(2)) and systemic oxygen consumption (VO(2)) were calculated according to blood-gas analysis in arterial and central venous blood.

RESULTSAfter decompression, HR, CO, MAP, CVP, PAWP, PaO(2) and DO(2) showed no significant differences in the 6 h group when compared to SAP pigs. In the 9 h group, however, CO decreased significantly and HR, CVP, PAWP increased significantly after decompression than SAP only animals (all P < 0.05). PaO(2), ScvO(2) and DO(2) showed lower after 3 h of decompression compared with another two groups. VO(2) increased higher in IAH groups during 6 h of experiment than SAP pigs (all P < 0.05). Then VO(2) showed a trend to fall and no differences in three groups.

CONCLUSIONSThere are remarkable and relatively irreversible effects on global hemodynamics and oxygen metabolism in response to the decompression in different time after sustained IAH with the underlying condition of SAP. The results of this study are in favor of a decompression in patients of SAP with IAH in early time.