Acute severe pancreatitis is a disease caused by various etiologies, characterized by local necrosis, inflammation, and infection of the pancreas, accompanied by systemic inflammatory response and persistent organ failure. The current mortality rate is still as high as 17%.

The course of acute severe pancreatitis can generally be divided into three periods. First, the acute response period, occurring up to about two weeks after onset, is characterized by a systemic inflammatory response. Second, the systemic infection period, from two weeks to about two months, is characterized by infection of pancreatic or peripancreatic necrosis. Third, the residual infection period, occurring two to three months later, where the main clinical manifestation is systemic malnutrition.