A 54-year-old man with no past medical history presents to the emergency department with 24 hours of abdominal pain. The pain started the day prior to presentation in the epigastrium and is still most intense there, but also radiates to the back. He denies similar episodes in the past. In addition to his pain, he has suffered three episodes of non-bloody, non-bilious vomiting. He takes no medications. He consumes approximately 15 alcoholic beverages per week, mostly on the weekends, and admits to 9 drinks on the day prior to symptom onset.
The patient is afebrile, his heart rate is 115 beats per minute, and other vital signs are normal. He is uncomfortable lying in bed and has diffuse mild abdominal tenderness, with the most severe tenderness in the epigastrium. His laboratory evaluation is notable for a white blood cell count of 12, an amylase of 1500 U/L, and a lipase of 780 U/L.
Acute pancreatitis is the most common gastrointestinal disorder requiring hospitalization in the United States, and its incidence appears to be increasing.1 In the United States, cases are evenly distributed between men and women, although alcohol is more commonly the cause in men and gallstones are more commonly the inciting factor in women. The incidence rises with increasing age, although the greatest number of cases occur in patients in the fifth or sixth decade of life. Pancreatitis affects black patients 2 to 3 times more frequently than the white population.1,2
The most common causes of pancreatitis are ethanol ingestion and gallstones. Less frequent causes include instrumentation of the bile or pancreatic ducts (endoscopic retrograde cholangiopancreatography [ERCP]), medications (especially diuretics, anti-epileptics, and protease inhibitors), hypertriglyceridemia, hypercalcemia, congenital anatomic or genetic conditions (e.g., pancreas divisum or cystic fibrosis transmembrane receptor [CFTR] mutation), mumps, pancreatic neoplasm, autoimmune disease, and trauma or hypoperfusion. In 10% to 15% of cases a cause is not identified.
Chronic pancreatitis has an incidence rate 15% to 30% that of acute pancreatitis.3 While the incidence of acute pancreatitis continues to increase with age, chronic pancreatitis incidence plateaus in middle age. Like acute pancreatitis, it is more common in blacks than in whites. The most important risk factors are alcohol use and smoking, but a range of genetic mutations (such as in CFTR and SPINK-1), autoimmune conditions, and environmental stimuli may be important contributors.4
Most acute pancreatitis is mild and self-limited. Approximately 20% of patients develop some degree of necrosis of the pancreatic parenchyma. Of these, about 30% develop infected pancreatic necrosis requiring intervention. The overall mortality is 2% to 4%.5
The pathophysiology of acute pancreatitis is poorly understood. Among patients with risk factors (heavy alcohol use, gallstones, hypercalcemia, etc.), only a minority develops acute pancreatitis over a lifetime, and the factors differentiating these ...