A. Introduction. Pancreatitis is a term that indicates inflammation of the pancreas.
a. Acute pancreatitis results from the leakage of pancreatic enzymes into pancreatic tissue, leading to autodigestion. Because acute pancreatitis is more common than chronic pancreatitis, acute pancreatitis is the focus of this chapter.
b. Chronic pancreatitis. Causes are varied and ultimately lead to destruction of the pancreatic tissue. The process usually starts with multiple episodes of acute pancreatitis, which subsequently leave the patient with a damaged pancreas. Patients may present with pain and/or weight loss due to fat and protein malabsorption.
B. Clinical Manifestations of Acute Pancreatitis
a. Symptoms usually include the abrupt onset of epigastric pain that lasts for hours to days and radiates to the back, nausea and vomiting, sweating, weakness, and anxiety. The patient often feels better when sitting up and leaning forward.
b. Physical examination findings
i. The patient may be febrile, tachycardic, tachypneic, and hypotensive.
ii. The skin of the periumbilical area may be discolored (Cullen’s sign). Flank ecchymoses (Grey Turner’s sign) may be present.
iii. The abdomen is hypoactive with mild distention (because of ileus). Upper abdominal and epigastric tenderness (usually without rebound or rigidity) is present.
c. Laboratory findings
i. Elevated serum amylase and lipase are the hallmarks of acute pancreatitis.
ii. Other findings may include leukocytosis (12,000–15,000/μL), hypoalbuminemia, hyperglycemia, and elevated aspartate aminotransferase (AST, SGOT), alkaline phosphatase, and bilirubin.
C. Causes of Acute Pancreatitis. There are numerous causes of pancreatitis. The simplest way to remember the most important of these causes is with the mnemonic, “BAD HITS.” (HINT: If you move the “S” in front of the “H,” the mnemonic will be easier to remember but more difficult to utter in public.)
MNEMONIC: Common Causes of Acute Pancreatitis (“BAD HITS”)
Hyperlipidemia or Hypercalcemia
Idiopathic or Infectious
a. Biliary stones are the most common cause of acute pancreatitis in hospitalized patients.
b. Alcohol abuse is the most common cause of pancreatitis overall in the United States.
c. Drugs. Many drugs can cause acute pancreatitis, including thiazide diuretics, sulfa antibiotics, pentamidine, and some antiretroviral agents. Think of drug-induced pancreatitis in patients who do not drink alcohol.
d. Hyperlipidemia (types I, IV, V). Pancreatitis usually does not occur in hyperlipidemic patients until their serum triglyceride level exceeds 1000 mg/dL.
e. Idiopathic causes. In 15% of patients, no obvious cause of pancreatitis is identified; however, many authors implicate pancreas divisum (a congenital defect), autoimmune pancreatitis, or microlithiasis as the cause. Pancreatic malignancy can also cause acute pancreatitis.
f. Infectious etiologies include mumps, cytomegalovirus (CMV), human immunodeficiency virus (HIV), and infections caused by Escherichia coli.
g. Trauma. Blunt, rather than penetrating, trauma is most often responsible for pancreatitis. Blunt trauma may cause ductal disruption, leakage of pancreatic enzymes, and autodigestion of the pancreas leading to pancreatitis.
h. Surgical. Postsurgical pancreatitis occurs in 3% of patients undergoing ERCP. The rate is higher (up to 25%) in patients with suspected sphincter of Oddi dysfunction.
i. Scorpion stings. This cause is really only important to know for resident’s report or on attending rounds. Scorpion stings are a common cause of pancreatitis in the Caribbean islands of Trinidad and Tobago.
D. Approach to the Patient. The diagnosis is based on finding elevated serum amylase or lipase levels in the context of an appropriate clinical setting. Imaging studies that may be helpful include abdominal ultrasound and computed tomography (CT), although CT is unnecessary for most cases because the diagnosis is clinically evident. When a patient presents with pancreatitis, you should:
a. Determine the cause of the pancreatitis.
b. Assess the severity and estimate the prognosis. Because the serum amylase and lipase levels do not correlate with severity, Ranson’s criteria are used to assess severity and prognosis.
i. Ranson’s criteria are assessed at admission and during the initial 48 hours.
MNEMONIC: Ranson’s Criteria During the Initial 48 Hours (“BaCH wasn’t a SOB”)
Base deficit >4 mEq/L
Calcium <8 mg/dL
Hematocrit decrease >10%
Sequestration of fluid >6 L
Oxygen <60 mm Hg
Blood urea nitrogen (BUN) increase of >5 mg/dL
ii. As the number of criteria met increases, so too does the mortality rate.
E. Treatment. Treatment is primarily supportive and includes bowel rest, volume resuscitation, pain control, and management of respiratory distress and renal failure. Contrary to popular belief, early feeding of patients with pancreatitis (as opposed to prolonged bowel rest) may be associated with improved outcomes. Nasogastric tubes are used for gastric decompression in patients with persistent vomiting. If gallstones are thought to be the cause, ERCP may be indicated. Cholecystectomy should only be considered after the patient recovers from the acute episode.
a. Pancreatic abscess should be suspected if the patient worsens after initial improvement. Persistent pain and fever are clues to the occurrence of an abscess, and CT scans can help make the diagnosis. Radiology-guided drainage or surgical intervention is often necessary in this group of patients.
b. Pancreatic pseudocyst occurs in 10%–20% of patients and usually does not require specific treatment unless it has been present for longer than 6 weeks, is larger than 5 cm in diameter, or is accompanied by significant symptoms.
c. Renal failure and respiratory failure are the two most common systemic complications and can be life-threatening.
Suggested Further Readings
Forsmark CE, Vege SS, Wilcox CM. Acute pancreatitis. N Engl J Med 2016;375:1972–81.Find this resource:
Pedersen SB, Langsted A, Nordestgaard BG. Nonfasting mild-to-moderate hypertriglyceridemia and risk of acute pancreatitis. JAMA Intern Med 2016;176:1834–42.Find this resource: