Abstract
The Japanese criteria for severity assessment (Japanese severity scoring system) are useful for grading the severity of acute pancreatitis. However, the Japanese criteria are cumbersome and complicated. This article reviews issues on the Japanese criteria for severity assessment. The Japanese scoring system is based on 18 prognostic factors of clinical signs, laboratory test data, and CT grade. It is often difficult to evaluate all items in the Japanese criteria during an emergency. There are some tautological factors that show the same clinical condition in acute pancreatitis. Initial fluid replacement directly affects some prognostic factors. The CT grade based on plain CT findings is not reliable to evaluate severity of acute pancreatitis. Although the severity is classified into three categories (mild, moderate and severe) in the Japanese critereia, there is no difference in the mortality rate and therapeutic strategy between mild and moderate acute pancreatitis. New criteria for assessment of the severity are now being developed.