Chapter 23: Pancreatitis

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LEARNING OBJECTIVES

INTRODUCTION

The pancreas is a gland in the abdomen lying in the curvature of the stomach as it empties into the duodenum. It functions primarily as an exocrine gland but also has endocrine function. The exocrine cells of the pancreas are called acinar cells that produce and store digestive enzymes that mix with a bicarbonate-rich solution released from duct cells to produce pancreatic juice. This juice is released through the ampulla of Vater into the duodenum to aid in digestion and buffer acidic fluid released from the stomach (Figure 23–1).¹

Pancreatic enzymes are produced and stored as inactive proenzymes within zymogen granules to prevent autolysis and digestion of the pancreas. Amylase and lipase are released from the zymogen granules in the active form, whereas the proteolytic enzymes are activated in the duodenum by enterokinase. Enterokinase triggers the conversion of trypsinogen to the active protease trypsin, which then activates the other proenzymes to their active enzymes. The pancreas contains a trypsin inhibitor to prevent autolysis.

ACUTE PANCREATITIS

EPIDEMIOLOGY AND ETIOLOGY

In the Western Hemisphere, acute pancreatitis (AP) is caused mainly by ethanol use/abuse and gallstones (cholelithiasis). Ethanol use accounts for about 30% of AP cases and gallstones about 30% to 40% of cases. Other common causes include hypertriglyceridemia, endoscopic retrograde cholangiopancreatography (ERCP), pregnancy, and autodigestion due to early activation of pancreatic enzymes. Numerous medications have been implicated as causes of AP, but other causes should be ruled out before discontinuing a medication indefinitely (Table 23–1).²

PATHOPHYSIOLOGY

Ethanol abuse may cause precipitation of pancreatic enzymes in pancreatic ducts, leading to chronic ...