Classification of severity of acute pancreatitis

classification of acute pancreatitis

Severity of acute pancreatitis is divided into 3 categories by the Atlanta classification. It provides definitions of the clinical and radiologic severity of acute pancreatitis:

• mild acute pancreatitis
  • characterised by
    • absence of organ failure
    • absence of local or systemic complications
    • patients
      • are usually discharged during the early phase - normally discharged 3- 7 days of onset of illness
      • usually do not require pancreatic imaging
  • mortality is very rare in this group of patients (1)
    
    
• moderately severe pancreatitis
  • this phase is characterised by the presence of transient organ failure (that resolves within 48 h) and/ or local or systemic complications in the absence of persistent organ failure e.g. -
    • peripancreatic collection (a symptomatic local complication) - causes prolonged abdominal pain, leucocytosis and fever, or that prevents the ability to maintain nutrition orally
    • symptomatic systemic complication - exacerbation of coronary artery disease or chronic lung disease precipitated by the acute pancreatitis
  • the condition may resolve
    • patient may recover without intervention or may require prolonged specialist care
      • without intervention e.g. - in transient organ failure or acute fluid collection
      • may require prolonged specialist care e.g. - in extensive sterile necrosis without organ failure (1)
• severe acute pancreatitis
  • the patient with severe acute pancreatitis has persistent organ failure (>48 hours) Organ failure which occurs during the early phase is set in motion by the activation of the cytokine cascades resulting in systemic inflammatory response syndrome (SIRS)
    • persistent organ failure may be single or multiple organ failure
    • in patients with persistent organ failure
      • one or more local complications may be present
      • if developed within the first few days, patients are at increased risk of death (reported mortality is between 36-50%)
        • extremely high mortality is seen in patients who develop infected necrosis
          
          
    • with persistent SIRS, there is an increased risk that the pancreatitis will be complicated by persistent organ failure. These patients should be considered to have severe acute pancreatitis and treated accordingly (1)
      
      

Persistent or transient organ failure:

• the Modified Marshall System is used to evaluate organ failure

• a score of 2 or more over a period of more than 48 hours for any one of the three organ systems is defined as persistent organ failure while if it is present for less than 48 hours, is known as transient organ failure
• level of severity should be assessed during the disease process and hospital stay using this scoring system (3)

Reference:

• (1) Banks PA et al. Classification of acute pancreatitis--2012: revision of the Atlanta classification and definitions by international consensus. Gut. 2013;62(1):102-11.
• (2) Johnson CD, Besselink MG, Carter R. Acute pancreatitis. BMJ. 2014;349:g4859
• (3) Sureka B et al. Imaging lexicon for acute pancreatitis: 2012 Atlanta Classification revisited. Gastroenterol Rep (Oxf). 2016;4(1):16-23