Chapter 42. Pancreatitis and Cholecystitis

Acute pancreatitis (AP) is a common cause of abdominal pain, and the diagnosis is based primarily on the patient's history and clinical examination findings. The severity of the disease may range from mild local inflammation to multisystem organ failure secondary to a systemic inflammatory response. Cholelithiasis and alcohol abuse are the most common causes, but there are many potential etiologies. Patients without risk factors often develop pancreatitis secondary to medications or severe hyperlipidemia. Commonly used medications associated with pancreatitis include acetaminophen, carbamazepine, enalapril, estrogens, erythromycin, furosemide, hydrochlorothiazide, opiates, steroids, tetracycline, and trimethoprim-sulfamethoxazole.

Clinical Features

The most common symptom is a midepigastric, constant, boring pain radiating to the back, which is often associated with nausea, vomiting, abdominal distention, and exacerbation in the supine position. Low-grade fevers, tachycardia, and hypotension may be present. Epigastric tenderness is common, whereas peritonitis is a late finding.

Physical finding are dependent on the severity of disease. Physical examination findings include epigastric tenderness but tenderness may localize more to the right or left upper quadrant of the abdomen. Bowel sounds may be diminished and abdominal distention may be present secondary to ileus. Refractory hypotensive shock, renal failure, fever, altered mental status, and respiratory failure may accompany the most severe disease.

Diagnosis and Differential

The diagnosis should be suspected by the history and physical examination. The presence of two of the three following features makes the diagnosis more likely: (1) history and examination findings consistent with acute pancreatitis, (2) lipase or amylase levels at least 2 to 3 times the upper limit of normal, or (3) imaging findings consistent with pancreatic inflammation. Serum lipase and amylase are the most common tests used to assist in the diagnosis but lipase is the preferred diagnostic test as it is more accurate. There are many sources of extrapancreatic amylase, making it relatively nonspecific. Normal serum amylase does not exclude the diagnosis of acute pancreatitis. There is no benefit to ordering both tests. The absolute levels do not correlate with the severity of disease.

A CBC will identify leukocytosis or anemia. Liver studies can demonstrate associated biliary involvement. An elevated alkaline phosphatase level suggests biliary disease and gallstone pancreatitis. Persistent hypocalcemia (<7 milligrams/100 mL), hypoxia, increasing serum urea nitrogen, and metabolic acidosis are associated with a potentially complicated course.

Imaging can help confirm the diagnosis of pancreatitis, evaluate biliary involvement, and exclude causes of abdominal pain. Abdominal CT scan is preferred over ultrasound as the latter is often limited by bowel gas overlying the pancreas. In the face of a typical clinical picture and laboratory results, emergency imaging may not be needed.

The differential diagnosis includes referred chest pain secondary to ischemic heart disease, pulmonary pathology such as pneumonia or empyema, hepatitis, cholecystitis or biliary colic, ascending cholangitis, renal colic, small bowel obstruction, peptic ulcer disease or gastritis, and acute aortic pathology such as aneurysm or dissection.

Emergency Department Care and Disposition

Care for the patient with pancreatitis includes fluid resuscitation; management of nausea, vomiting, and pain; and diligent monitoring of vital signs and pulse oximetry.

1. Initiate aggressive fluid resuscitation with crystalloid intravenous fluid. Pressors are indicated for hypotension not responsive to adequate fluid resuscitation.

2. Patients should be made npo to allow pancreatic rest.

3. Administer antiemetics, such as ondansetron 4 milligrams or prochlorperazine 5 to 10 milligrams to reduce vomiting (see Chapter 36). A nasogastric tube is indicated only for intractable vomiting.

4. Administer parenteral analgesia for patient comfort. Intravenous opioids such as morphine 0.1 milligram/kilogram are often required.

5. Administer oxygen to maintain a pulse oximetry reading of 95% oxygen saturation. Treat respiratory failure aggressively.

6. Treat patients with infected pseudocyst, abscess, or infected peripancreatic fluid with imipenem-cilastatin 500 milligrams IV, meropenem 1 gram IV, or ciprofloxacin 400 milligrams IV and metronidazole 500 milligrams IV.

7. Patients with severe systemic disease will require intubation, intensive monitoring, bladder catheterization, and transfusion of blood and blood products as needed. Symptomatic hypocalcemia should be corrected. Laparotomy may be indicated for hemorrhage or abscess drainage.

8. Consult gastroenterology for patients with gallstone pancreatitis for endoscopic retrograde cholangiopancreatography (ERCP) and sphincterotomy.

9. Most patients will require hospitalization. Patients who demonstrate poor prognostic signs (dropping hemoglobin, poor urine output, persistent hypotension, hypoxia, acidosis, or hypocalcemia) despite aggressive early treatment should be admitted to the intensive care unit with surgical consultation.

10. Patients with mild disease, no biliary tract disease, and no evidence of systemic complications may be managed as outpatients with close follow-up if they tolerate clear liquids and oral analgesics in the ED. Instruct patients to increase their diet as tolerated once nausea is controlled.

Biliary tract emergencies most often result from obstruction of the gallbladder or biliary duct by gallstones. The 4 most common biliary tract emergencies caused by gallstones are biliary colic, cholecystitis, gallstone pancreatitis, and ascending cholangitis. Biliary disease affects all age groups, especially diabetics and the elderly. Gallstones, although common in the general population, remain asymptomatic in most patients. Common risk factors for gallstones and cholecystitis include advanced age, female sex and parity, obesity, rapid weight loss or prolonged fasting, familial tendency, use of some medications, Asian ancestry, chronic liver disease, and hemolytic disorders (eg, sickle cell disease).

Clinical Features

Patients with biliary disease present with a wide range of symptoms. Biliary colic may present with epigastric or right upper quadrant pain, may range from mild to severe, and, although classically described as intermittent or colicky, is often constant. Nausea and vomiting are usually present. Pain may be referred to the right shoulder or left upper back. It may begin after eating but often bears no association to meals. Acute episodes of biliary colic typically last for 1 to 5 hours, followed by a gradual or sudden resolution of symptoms. Recurrent episodes are usually infrequent, generally at intervals longer than 1 week. Biliary colic seems to follow a circadian pattern, with highest incidence of symptoms between 9 pm and 4 am.

Physical examination commonly demonstrates right upper quadrant or epigastric tenderness without findings of peritonitis.

Acute cholecystitis presents with pain similar to that of biliary colic that persists for longer than the typical 5 hours. Fever, chills, nausea, emesis, and anorexia are common. Past history of similar attacks or known gallstones may be reported. As the gallbladder becomes progressively inflamed, the initial poorly localized upper abdominal pain often becomes sharp and localized to the right upper quadrant. The patient may have moderate to severe distress and may appear toxic. Choledocholithiasis often presents with midline pain that radiates to the middle of the back.

Examination findings include tenderness in the right upper quadrant or epigastrum, and Murphy's sign, that is increased pain or inspiratory arrest during deep subcostal palpation of the right upper quadrant during deep inspiration. Murphy's sign is the most sensitive physical examination finding for the diagnosis of cholecystitis. Generalized abdominal rigidity suggests perforation and diffuse peritonitis. Volume depletion is common, but jaundice is unusual. Acalculous cholecystitis occurs in 5% to 10% of patients with cholecystitis, has a more rapid, aggressive clinical course, and occurs more frequently in patients with diabetes, the elderly, trauma or burn victims, after prolonged labor or major surgery, or with systemic vasculitides.

Ascending cholangitis, a life-threatening condition with high mortality, results from complete biliary obstruction (often a common bile duct stone; less commonly a tumor) with bacterial superinfection. Patients often present in extremis with jaundice, fever, confusion, and shock. Examination findings can be subtle. Patients commonly have focal right upper quadrant pain and nausea. Jaundice may or may not be present. The Charcot triad of fever, jaundice, and right upper quadrant pain is suggestive but all three components are usually not present at once.

Diagnosis and Differential

Suspicion of gallbladder or biliary tract disease must be maintained in any patient who presents with upper abdominal pain. The differential diagnosis is similar to that of acute pancreatitis (see Pancreatitis: Diagnosis and Differential, earlier).

Patients with uncomplicated biliary colic usually have normal laboratory findings. The diagnosis is usually made based on the patient presentation, response to therapy, and examining the test results in aggregate.

Laboratory studies that may aid in diagnosis include a white blood cell count; leukocytosis with left shift suggests acute cholecystis, pancreatitis, or cholangitis, but a normal white blood cell count does not exclude them. Serum bilirubin and alkaline phosphatase levels may be normal or mildly elevated in patients suffering from biliary colic or cholecystitis. Serum bilirubin and alkaline phosphatase levels are usually elevated in cases of choledocholithiasis and ascending cholangitis. Serum lipase or amylase levels should be checked to help exclude associated pancreatitis.

Ultrasound of the hepatobiliary tract is the initial diagnostic study of choice for patients with suspected biliary colic or cholecystitis and has a sensitivity and specificity for cholecystitis of 94% and 78% respectively. It can detect stones as small as 2 mm and signs of cholecystitis which include a thickened gallbladder wall (>3 to 5 mm), gallbladder distention (>4 cm in short-axis view), and pericholecystic fluid. A positive sonographic Murphy's sign is very sensitive for diagnosis of cholecystitis when it is elicited during the scan. Ultrasound has a strong positive predictive value (92%) when both a sonographic Murphy's sign and gallstones are present. Choledocholithiasis is suggested when the common bile duct diameter is greater than 5 to 7 mm. (Fig. 42-1).

Computed tomography of the abdomen is most useful when other intraabdominal processes are suspected. Radionuclide cholescintigraphy (technetium-iminodiacetic acid [HIDA]) or diisopropyl iminodiacetic acid ([DISIDA] scans) offers a sensitivity of 97% and a specificity of 90% for cholecystitis. A reasonable emergency department approach to suspected cholecystitis would be to obtain an ultrasound scan and then a radionuclide scan if ultrasound fails to establish the diagnosis.

Emergency Department Care and Disposition

Care for the patient with biliary disease includes fluid resuscitation and management of nausea, vomiting, and pain. Only biliary colic can be managed without the aid of consultants. ED treatment includes the following measures:

1. Initiate aggressive fluid resuscitation with crystalloid intravenous fluid. Pressors are indicated for hypotension not responsive to adequate fluid resuscitation.

2. Patients should be made npo to allow pancreatic rest.

3. Administer antiemetics, such as ondansetron 4 milligrams or prochlorperazine 5 to 10 milligrams to reduce vomiting (see Chapter 36). A nasogastric tube is indicated only for intractable vomiting.

4. Administer parenteral analgesia for patient comfort. Intravenous opioids such as morphine 0.1 milligram/kilogram are often required. The intravenous nonsteroidal anti-inflammatory drug (NSAID) ketorolac 30 milligrams IV may also be helpful.

5. A nasogastric tube to low suction should be considered if the patient is distended or actively vomiting, or if vomiting is intractable to antiemetics.

6. Patients with acute biliary obstruction may require urgent decompression via endoscopic sphincterotomy of the ampulla of Vater.

7. Early antibiotic therapy should be initiated in any patient with suspected cholecystitis or cholangitis. Adequate therapy for uncomplicated cases of cholecystitis includes a parenteral third-generation cephalosporin (cefotaxime or ceftriaxone 1 gram IV q12 to q24h) plus metronidazole 500 milligrams IV. Those with ascending cholangitis, sepsis, or obvious peritonitis are best managed with triple coverage by using ampicillin (0.5 to 1.0 gram IV q6h), gentamicin (1 to 2 milligrams/kilogram IV q8h), and clindamycin (600 milligrams IV q6h, or the equivalent substitutes (eg, metronidazole for clindamycin, third-generation cephalosporins or piperacillin/tazobactam, or a fluoroquinolone for ampicillin).

8. Patients diagnosed with acute cholecystitis, gallstone pancreatitis, or ascending cholangitis require immediate surgical consultation with hospital admission. Patients with choledocholithiasis, gallstone pancreatitis, or ascending cholangitis may also require urgent gastroenterology consultation to facilitate ERCP and sphincterotomy. Signs of systemic toxicity or sepsis warrant admission to the intensive care unit pending surgical treatment.

9. Patients with uncomplicated biliary colic whose symptoms abate with supportive therapy within 4 to 6 hours of onset can be discharged home if they are able to maintain oral hydration. Oral opioid analgesics may be prescribed for the next 24 to 48 hours for the common residual abdominal aching. Timely outpatient follow-up should be arranged with a surgical consultant or the patient's primary care physician. The patient should be carefully instructed to return to the emergency department if fever develops, abdominal pain worsens, for intractable vomiting, or if another significant attack occurs before follow-up.