Fig. 1

Pathophysiology of fluid loss/hypovolemia in patients with severe acute pancreatitis. The intrapancreatic activation of proteolytic enzymes causes local tissue inflammation with leukocyte activation, cytokines, and reactive oxygen species release. At a systemic level, the massive release of pro-inflammatory cytokines from the injured pancreas leads to SIRS, causing an intravascular fluid loss through vasodilatation, cellular dysfunction, and increased capillary permeability. Ileus, vomit, decreased fluid intake, and increased insensible losses further contribute to intravascular fluid depletion. If not interrupted, this vicious cycle leads to a severe hypovolemic and distributive shock and ultimately to MOF. IL-1 Interleukin-1; TNF-α Tumor necrosis factor; IL-6 Interleukin-6; SIRS Systemic inflammatory response syndrome; GI Gastrointestinal; MOF Multiorgan failure