Management of Acute Pancreatitis

1. Diagnosis of acute pancreatitis
    1. Serum lipase should be performed in all patients with a suspected diagnosis of acute pancreatitis. A 3-fold elevation of serum lipase from the upper limit of normal is required to make the diagnosis of acute pancreatitis.
    2. Ultrasonography should be performed in all patients at baseline to evaluate the biliary tract and in particular to determine if the patient has gall stones and/or a stone in the common bile duct.
    3. Magnetic resonance cholangiopancreatography(MRCP) is recommended only in patients in whom there is elevation of liver enzymes and in whom the common bile duct is either not visualized adequately or is found to be normal on ultrasound.
    4. Computed tomography (CT) should be performed selectively when 1) a patient presents with significant abdominal pain and a broad differential diagnosis which includes acute pancreatitis, or 2) in patients with suspected local complications of acute pancreatitis (e.g. peritonitis, signs of shock, suggestive ultrasound findings). CT for assessment of local complications is most useful after 48-72 hours after the onset of symptoms rather than at the time of admission. Unless contraindicated (e.g. renal dysfunction), intravenous contrast should be given in order to assess for pancreatic necrosis once patients are adequately fluid resuscitated and normovolemia restored.
2. Assessment of severity
    1. A serum C reactive protein (CRP) level of 14 286 nmol/L (150 mg/dL) or greater at baseline or in the first 72 hours is suggestive of severe acute pancreatitis, and is predictive of a worse clinical course. Thus, CRP should be performed at admission and daily for the first 72 hours after admission.
    2. Acute Physiologic Assessment and Chronic Health Evaluation APACHE II Scores should be calculated on admission and daily for the first 72 hours after admission. An APACHE II Score of 8 or higher at baseline or in the first 72 hours is suggestive of severe acute pancreatitis, and is predictive of a worse clinical course.
    3. Severe acute pancreatitis should be diagnosed if a patient exhibits signs of persistent organ failure for more than 48 hours despite adequate intravenous fluid resuscitation.
3. Supportive care
    1. Supportive care, including resuscitation with isotonic intravenous fluids (e.g. Ringer’s Lactate solution), pain control, and mobilization should be the mainstay of treatment of patients with mild acute pancreatitis
    2. Careful consideration of transfer to a monitored unit should be made in patients with 1) Severe acute pancreatitis based on APACHE II Score greater than 8, CRP greater than 14 286 nmol/L (150 mg/L), or organ dysfunction for more than 48 hours despite adequate resuscitation; 2) Evidence of present or evolving organ dysfunction defined as follows:

      ● Respiratory (PaO2/FiO2 ≤ 300, or respiratory rate > 20 breaths per minute

      ● Cardiovascular (hypotension despite aggressive fluid resuscitation [systolic BP <90 mm Hg off of inotropic support or drop of sBP > 40], need for vasopressors [not fluid responsive], or pH <7.3)

      ● Renal (>1.5 fold increase in serum creatinine over 7 days, increase of >26.5μmol in serum creatinine over 48 hours, urine output <0.5ml/kg/h for >6 hours and/orNeed for aggressive, ongoing fluid resuscitation defined as evidence of severe haemoconcentration (Hb > 160, HCT > 0.500)

      Patients with one or more of the above criteria and a body mass index (BMI) above 30 (or BMI > 25 in Asian populations) should be monitored carefully, with a lower threshold for transfer to a monitored unit given the worse course of disease in the obese patient population.

4. Nutrition
    1. Patients who present with mild acute pancreatitis should receive a regular diet on admission. If patients are unable to tolerate an oral diet owing to abdominal pain, nausea, vomiting, or ileus, they may be allowed to self-advance their diet from withholding oral food and fluids (NPO) to a regular diet as tolerated.
    2. In patients with severe acute pancreatitis, enteral nutrition should be commenced as soon as possible following admission (within 48 hours). A nasojejunal tube is not superior to feeding by nasogastric feeding tube; thus, commencement of feeds should not be delayed for the purpose of placing a nasojejunal feeding tube. Enteral feeding is recommended over parenteral nutrition.
5. Prophylactic antibiotics
  1. Prophylactic antibiotics
    1. Prophylactic antibiotics are not recommended in patients with mild or severe acute pancreatitis
6. Diagnosis and Management of Local Complications of Acute Pancreatitis
    1. Repeat CT should be considered with new (or unresolving) evidence of infection (eg: leukocytosis, fever) without a known source, new inability to tolerate oral/enteral feeds, change in haemodynamic status, or evidence of bleeding.
    2. Patients who have extensive necrotizing acute pancreatitis, who show no clinical signs of improvement following appropriate initial management, or in whom other complications develop should be managed in consultation with, or at institutions with therapeutic endoscopy, interventional radiology, surgical and intensive care expertise in dealing with severe acute pancreatitis.
    3. Patients with acute peripancreatic fluid collections with no radiological or clinical suspicion of sepsis should be observed, and image-guided fine needle aspiration (FNA) should be avoided due to the risk of introducing infection into a sterile collection.
    4. When there is radiological or clinical suspicion of infected necrosis in patients with acute necrotic collections (ANCs) or walled-off pancreatic necrosis (WOPN), image-guided FNA with culture should be performed to distinguish infected from sterile necrosis.
    5. Sterile necrosis based on negative FNA and/or stable clinical picture should be managed non-operatively, and antibiotics are not indicated. The exception is unstable patients in whom sepsis is suspected but no source has been identified: treatment with broad spectrum antibiotics on speculation may be indicated while an appropriate work up (bacterial and fungal cultures, CT) is carried out.
    6. Antibiotics should be prescribed only in patients with infected necrosis confirmed by FNA or if there is gas within a collection visualized on CT scan. Antimicrobial therapy should be tailored to FNA culture speciation and sensitivities; however, empiric treatment with antibiotics active against the most common pathogens in infected pancreatic necrosis (Escherichia coli, Bacteroides species, Enterobacter species, Klebsiella species and Streptococcus faecalis, as well as other gram positive organisms such as Staphylococcus epidermidis and Staphylococcus aureus) may be considered until final culture results are available.
    7. In patients with FNA-confirmed infections of ANCs or WOPN, a step-up approach of antibiotics and image-guided drainage, followed by surgical intervention if necessary, is indicated. Surgical consultation should occur early; however, surgical intervention should be delayed until later in the course of disease whenever possible. Minimally invasive image-guided or endoscopic drainage is recommended as first line therapy, and multiple drains may be necessary. Surgery should be considered for cases in whom less invasive approaches fail, but should be delayed long enough to allow demarcation of necrotic pancreatic tissue.
    8. Pancreatic pseudocysts which are asymptomatic should be managed non-operatively. Intervention is indicated in pseudocysts that are symptomatic, infected, or increasing in size on serial imaging, and should be performed in a high volume centre.
7. Management of patients with acute gallstone pancreatitis
    1. Endoscopic retrograde cholangiopancreatography (ERCP) should be performed early (within 24-48 hours) in patients with acute gallstone pancreatitis associated with bile duct obstruction or cholangitis. In unstable patients with severe acute gallstone pancreatitis and associated bile duct obstruction or cholangitis, placement of a percutaneous transhepatic gallbladder drainage tube should be considered if ERCP is not safely feasible.
    2. Cholecystectomy should be performed during the index admission in patients who have mild acute pancreatitis and should be delayed until clinical resolution in patients who have severe acute pancreatitis.
    3. If cholecystectomy is contraindicated in patients because of medical comorbidities, ERCP and sphincterotomy should be considered prior to discharge in patients with acute gall stone pancreatitis.