ESSENTIALS OF DIAGNOSIS
Gallstone disease and alcohol are the most common causes of acute pancreatitis; other causes include hypertriglyceridemia, drugs, and specific disorders of the biliary tree and pancreas.
Diagnosis is usually made based on a history of acute abdominal pain; a threefold elevation in serum amylase or lipase, or both; or an abnormal abdominal computed tomography (CT) scan showing changes of acute pancreatitis.
Severe acute pancreatitis is characterized by persistent (>48 hours) organ failure (systemic blood pressure <90 mm Hg, PaO2 <60 mm Hg, creatinine >2.0 mg/dL) or pancreatic necrosis.
Diagnosis of necrotizing pancreatitis is confirmed by contrast-enhanced abdominal CT scan or MRI scan.
Acute pancreatitis is an acute inflammatory disorder of the pancreas that involves the pancreas and peripancreatic tissues but can sometimes affect other organ systems. The initial evaluation of patients with acute pancreatitis involves determining the cause and assessing the severity of disease since this guides subsequent management.
Acute pancreatitis is the most common inpatient gastrointestinal diagnosis in the United States. There were 274,119 hospitalizations in 2012 for acute pancreatitis with a median length of stay of 4 days and median charges amounting to $11,402. The incidence rate of acute pancreatitis appears to be increasing without any changes in the short-term or long-term case fatality rates.
B. Causes and Risk Factors
The most common causes of acute pancreatitis in the United States are gallstones and alcohol abuse, accounting for 70–80% of cases. Table 26–1 lists other causes, including hypertriglyceridemia, drug reactions, iatrogenic causes (eg, postsurgical or endoscopic retrograde cholangiopancreatography [ERCP]), hereditary factors, and idiopathic causes.
Table 26–1.Causes of acute pancreatitis. |Favorite Table|Download (.pdf) Table 26–1. Causes of acute pancreatitis.
Biliary (eg, gallstones, gallbladder microlithiasis/sludge)
Drug-induced (see Table 26–2)
Surgery (eg, common bile duct exploration, sphincterotomy, splenectomy, distal gastrectomy)
Infectious (eg, ascariasis, clonorchiasis, mumps, toxoplasmosis, coxsackievirus, cytomegalovirus, tuberculosis, Mycobacterium avium complex)
PRSS1 (cationic trypsinogen) mutations: hereditary pancreatitis) CFTR (cystic fibrosis transmembrane conductance regulator) mutations
SPINK1 (serine protease inhibitor, Kazal type 1) mutations
Metabolic (eg, hypercalcemia, hypertriglyceridemia)
Neoplastic (eg, pancreatic or ampullary tumors)
Structural (eg, pancreatic divisum, annular pancreas, sphincter of Oddi dysfunction, periampullary diverticula, duodenal duplication cysts, choledochocele, anomalous pancreaticobiliary junction, regional enteritis
Toxic (eg, organophosphates, scorpion venom)
Traumatic (especially motor vehicle accidents)
The first attack of alcohol-induced acute pancreatitis typically occurs after many (eg, 8–10) years of heavy alcohol consumption, and recurrent episodes can be anticipated if alcohol abuse continues. Gallstone-induced pancreatitis occurs in the setting of choledocholithiasis and is believed to be related to transient or complete obstruction of pancreatic ductal flow or reflux of bile into the pancreatic duct. Hypertriglyceridemia-associated acute pancreatitis does not typically occur unless the triglyceride level exceeds 1000 mg/dL and is often seen in patients with type I and ...