Acute Pancreatitis I: Introduction

Acute pancreatitis involves rapid inflammation of the pancreas, while chronic pancreatitis progresses slowly and causes permanent damage. Acute pancreatitis develops suddenly from factors like gallstones or alcohol, whereas chronic pancreatitis results from long-term alcohol abuse or persistent duct obstructions. Both conditions involve pancreatic inflammation but differ significantly in onset speed and tissue damage progression.

Common causes include gallstone obstruction of the pancreatic duct and excessive alcohol consumption. Less common causes include hypertriglyceridemia, hypercalcemia, abdominal trauma, certain medications like steroids and antibiotics, and viral or bacterial infections. Gallstones block digestive enzyme flow, while alcohol directly damages pancreatic tissue, triggering inflammation.

Harmful factors damage the pancreas, causing production of digestive enzymes like trypsin and phospholipase. Normally these enzymes activate in the small intestine, but in pancreatitis they activate prematurely within the pancreas itself. This premature activation initiates autodigestion, where enzymes destroy pancreatic tissue, triggering inflammation and cellular damage.

Autodigestion triggers release of inflammatory mediators including cytokines, chemokines, and proteins. These mediators cause fluid accumulation known as edema and, in severe cases, tissue death or necrosis. The inflammation damages blood vessels and surrounding tissues, potentially leading to organ failure and systemic complications in severe acute pancreatitis.

Acute pancreatitis is classified as mild or severe. Mild pancreatitis involves localized inflammation without organ complications, while severe pancreatitis involves systemic inflammation and risk of organ failure. In severe cases, patients may experience permanent decrease in pancreatic endocrine and exocrine function, leaving them susceptible to pancreatic necrosis and septic complications.

The pancreas produces digestive enzymes including trypsin, phospholipase, and elastase. These enzymes normally activate in the small intestine to aid food digestion. However, in acute pancreatitis, premature activation within the pancreas causes autodigestion and tissue destruction, initiating the inflammatory cascade that characterizes the disease.

Severe acute pancreatitis can cause permanent decrease in pancreatic endocrine and exocrine function. Patients become highly susceptible to complications including pancreatic necrosis, organ failure, and septic complications. Understanding acute pancreatitis clinical manifestations and management is essential for recognizing and treating these serious outcomes.