Intra-abdominal hypertension in acute pancreatitis.

The incidence of intra-abdominal hypertension (IAH) in patients with severe acute pancreatitis (SAP) is approximately 60-80%. It is usually an early phenomenon, partly related to the effects of the inflammatory process, causing retroperitoneal edema, fluid collections, ascites, and ileus, and partly iatrogenic, resulting from aggressive fluid resuscitation. It also can manifest at a later stage, often associated with local pancreatic complications. IAH is associated with impaired organ dysfunction, especially of the cardiovascular, respiratory, and renal systems. Using current definitions, the incidence of the clinical manifestation, abdominal compartment syndrome (ACS), has been reported as 27% in the largest study so far. Despite several intervention options, the mortality in patients developing ACS remains high: 50-75%. Prevention with judicious use of crystalloids is important, and nonsurgical interventions, such as nasogastric decompression, short-term use of neuromuscular blockers, removal of fluid by extracorporeal techniques, and percutaneous drainage of ascites should be instituted early. The indications for surgical decompression are still not clearly defined, but undoubtedly some patients benefit from it. It can be achieved with full-thickness laparostomy (midline or transverse subcostal) or through a subcutaneous linea alba fasciotomy. Despite the improvement in physiological variables and significant decrease in IAP, the effects of surgical decompression on organ function and outcome are less clear. Because of the significant morbidity associated with surgical decompression and the management of the ensuing open abdomen, more research is needed to define better the appropriate indications and techniques for surgical intervention.