Abstract
This revised classification document attempts to provide a universal system for categorizing the type and severity of acute pancreatitis. It also addresses shortcomings of the original 1992 guidelines that have emerged with improved understanding of disease pathogenesis. New definitions of early and late disease status are provided in addition to criteria for mild, moderate and severe acute pancreatitis.
The revised criteria defines diagnosis of acute pancreatitis as the presence of two of the following criteria: (i) abdominal pain consistent with acute pancreatitis, (ii) serum lipase or amylase activity greater than three times the upper limit of normal and (iii) characteristic findings on contrast-enhanced computed tomography (CECT). The type (interstitial oedematous pancreatitis or necrotizing pancreatitis) and presence of local complications are also assessed by CECT.
The main determinant of severity classification is the presence and duration of organ failure. Of note, the APACHE II and Ranson scoring systems (which include electrolyte, lactate dehydrogenase, alanine transaminase and acid– base analysis) are no longer recommended for assessing severity. Rather, the modified Marshall scoring system is used to subjectively define organ failure based on simple assessments of renal, cardiovascular and respiratory function. Within this system, cardiovascular and respiratory function scores are largely provided by clinical assessment while renal dysfunction is scored on extent of serum creati-nine increase above 134 μmol/L. This single scoring system approach should eliminate much of the confusion associated with categorizing disease severity; however, it fails to define criteria for patients with pre-existing renal disease and baseline creatinine above 134 μmol/L.
Overall the revised classification represents a shift from biochemical testing to radiological imaging for assessment of acute pancreatitis. However, pancreatic enzyme analysis is recommended as part of the initial diagnosis, and subsequent computed tomography imaging should only be conducted when there is high clinical suspicion of acute pancreatitis in the absence of significant enzyme elevation.