The current guidelines on the diagnosis and treatment of acute pancreatitis as published in the American Journal of Gastroenterology by the American College of Gastroenterology are summarized below.

IN SUMMARY:
During the past decade, there have been new understandings and developments in the diagnosis, etiology, and early and late management of the disease. As the diagnosis of AP is most often established by clinical symptoms and laboratory testing, contrast-enhanced computed tomography and/or magnetic resonance imaging of the pancreas should be reserved for patients in whom the diagnosis is unclear or who fail to improve clinically. Hemodynamic status should be assessed immediately upon presentation and resuscitative measures begun as needed. Patients with organ failure and/or the systemic inflammatory response syndrome (SIRS) should be admitted to an intensive care unit or intermediary care setting whenever possible. Aggressive hydration should be provided to all patients, unless cardiovascular and/or renal comorbidites preclude it. Early aggressive intravenous hydration is most beneficial within the first 12-24 h, and may have little benefit beyond. Patients with AP and concurrent acute cholangitis should undergo endoscopic retrograde cholangiopancreatography (ERCP) within 24 h of admission. Pancreatic duct stents and/or postprocedure rectal nonsteroidal anti-inflammatory drug (NSAID) suppositories should be utilized to lower the risk of severe post-ERCP pancreatitis in high-risk patients. Routine use of prophylactic antibiotics in patients with severe AP and/or sterile necrosis is not recommended. In patients with infected necrosis, antibiotics known to penetrate pancreatic necrosis may be useful in delaying intervention, thus decreasing morbidity and mortality. In mild AP, oral feedings can be started immediately if there is no nausea and vomiting. In severe AP, enteral nutrition is recommended to prevent infectious complications, whereas parenteral nutrition should be avoided. Asymptomatic pancreatic and/or extrapancreatic necrosis and/or pseudocysts do not warrant intervention regardless of size, location, and/or extension. In stable patients with infected necrosis, surgical, radiologic, and/or endoscopic drainage should be delayed, preferably for 4 weeks, to allow the development of a wall around the necrosis.

DEFINITIONS OF SEVERITY IN ACUTE PANCREATITIS – Atlanta Revision (2013):
1. Mild acute pancreatitis

• Absence of organ failure
• Absence of local complications

2. Moderately severe acute pancreatitis

• Local complications AND/OR
• Transient organ failure (<48 h)

3. Severe acute pancreatitis

• Persistent organ failure >48 hrs

CLINICAL FINDINGS ASSOCIATED WITH A SEVERE COURSE FOR INITIAL RISK ASSESSMENT:
1. Patient characteristics:

• Age > 55 years
• Obesity (BMI > 30 kg/m2)
• Altered mental status
• Comorbid disease

2. The systemic inflammatory response syndrome (SIRS) – Presence of >2 of the following criteria:

• pulse >90 beats/min
• REspirations >20/min or PaCO2 >32 mm Hg
• temperature >38 ° C or <36 °C
• WBC count >12,000 or <4,000 cells/mm3 or >10% immature neutrophils (bands)

3. Laboratory findings

• BUN >20 mg/dl
• Rising BUN
• HCT > 44%
• Rising HCT
• Elevated creatinine

4. Radiology findings

• Pleural effusions
• Pulmonary infiltrates
• Multiple or extensive extra-pancreatic collections

SUMMARY OF RECOMMENDATIONS:

1. DIAGNOSIS

• The diagnosis of AP is most often established by the presence of two of the three following criteria:

1. abdominal pain consistent with the disease
2. serum amylase and/or lipase greater than three times the upper limit of normal, and/or
3. characteristic findings from abdominal imaging

• Contrast-enhanced computed tomographic and/or magnetic resonance imaging of the pancreas should be reserved for patients in whom the diagnosis is unclear or who fail to improve clinically within the first 48-72 h after hospital admission

2. ETIOLOGY

• Transabdominal ultrasound should be performed in all patients with acute pancreatitis
• In the absence of gallstones and/or history of significant history of alcohol use, a serum triglyceride should be obtained and considered the etiology if > 1,000 mg/dl
• In a patient older than 40 years, a pancreatic tumor should be considered as a possible cause of acute pancreatitis
• Endoscopic investigation in patients with acute idiopathic pancreatitis should be limited, as the risks and benefits of investigation in these patients are unclear
• Patients with idiopathic pancreatitis should be referred to centers of expertise
• Genetic testing may be considered in young patients (<30 years old) if no cause is evident and a family history of pancreatic disease is present

3. INITIAL ASSESSMENT AND RISK STRATIFICATION

• Hemodynamic status should be assessed immediately upon presentation and resuscitative measures begun as needed
• Risk assessment should be performed to stratify patients into higher- and lower-risk categories to assist triage, such as admission to an intensive care setting
• Patients with organ failure should be admitted to an intensive care unit or intermediary care setting whenever possible

4. INITIAL MANAGEMENT

• Aggressive hydration, defined as 250-500 ml per hour of isotonic crystalloid solution should be provided to all patients, unless cardiovascular and/or renal comorbidites exist. Early aggressive intravenous hydration is most beneficial the first 12-24 h, and may have little benefit beyond
• In a patient with severe volume depletion, manifest as hypotension and tachycardia, more rapid repletion (bolus) may be needed
• Lactated Ringer’s solution may be the preferred isotonic crystalloid replacement fluid
• Fluid requirements should be reassessed at frequent intervals within 6 h of admission and for the next 24-48 h. The goal of aggressive hydration should be to decrease the blood urea nitrogen

5. ERCP IN ACUTE PANCREATITIS

• Patients with acute pancreatitis and concurrent acute cholangitis should undergo ERCP within 24 h of admission
• ERCP is not needed in most patients with gallstone pancreatitis who lack laboratory or clinical evidence of ongoing biliary obstruction
• In the absence of cholangitis and/or jaundice, MRCP or endoscopic ultrasound (EUS) rather than diagnostic ERCP should be used to screen for choledocholithiasis if highly suspected
• Pancreatic duct stents and/or postprocedure rectal nonsteroidal anti-inflammatory drug (NSAID) suppositories should be utilized to prevent severe post-ERCP pancreatitis in high-risk patients

6. THE ROLE OF ANTIBIOTICS IN ACUTE PANCREATITIS

• Antibiotics should be given for an extrapancreatic infection, such as cholangitis, catheter-acquired infections, bacteremia, urinary tract infections, pneumonia
• Routine use of prophylactic antibiotics in patients with severe acute pancreatitis is not recommended
• The use of antibiotics in patients with sterile necrosis to prevent the development of infected necrosis is not recommended
• Infected necrosis should be considered in patients with pancreatic or extrapancreatic necrosis who deteriorate or fail to improve after 7-10 days of hospitalization. In these patients, either

1. initial CT-guided fine needle aspiration (FNA) for Gram stain and culture to guide use of appropriate antibiotics or
2. empiric use of antibiotics without CT FNA should be given

• In patients with infected necrosis, antibiotics known to penetrate pancreatic necrosis, such as carbapenems, quinolones, and metronidazole, may be useful in delaying or sometimes totally avoiding intervention, thus decreasing morbidity and mortality
• Routine administration of antifungal agents along with prophylactic or therapeutic antibiotics is not recommended

7. NUTRITION IN ACUTE PANCREATITIS

• In severe AP, enteral nutrition is recommended to prevent infectious complications. Parenteral nutrition should be avoided unless the enteral route is not available, not tolerated, or not meeting caloric requirements
• Nasogastric delivery and nasojejunal delivery of enteral feeding appear comparable in efficacy and safety

8. THE ROLE OF SURGERY IN ACUTE PANCREATITIS

• In patients with mild AP, found to have gallstones in the gallbladder, a cholecystectomy should be performed before discharge to prevent a recurrence of AP
• In a patient with necrotizing biliary AP, in order to prevent infection, cholecystectomy is to be deferred until active inflammation subsides and fluid collections resolve or stabilize
• The presence of asymptomatic pseudocysts and pancreatic and/or extrapancreatic necrosis do not warrant intervention, regardless of size, location, and/or extension
• In stable patients with infected necrosis, surgical, radiologic, and/or endoscopic drainage should be delayed preferably for more than 4 weeks to allow liquefication of the contents and the development of a fibrous wall around the necrosis (walled-off necrosis)
• In symptomatic patients with infected necrosis, minimally invasive methods of necrosectomy are preferred to open necrosectomy