What laboratory value is most sensitive and specific for diagnosing acute pancreatitis?

The serum lipase level is the most sensitive and specific laboratory value for diagnosing acute pancreatitis. Lipase is an enzyme produced by the pancreas that helps in the digestion of fats. In the setting of acute pancreatitis, lipase levels typically rise within hours of the onset of symptoms and can remain elevated for several days, making it a reliable marker for the condition.

In comparison, serum amylase levels are also often measured in cases of suspected pancreatitis; however, they can rise in various other conditions, such as salivary gland disorders or intestinal obstruction, which can reduce their specificity. While C-reactive protein (CRP) is a marker of inflammation and can indicate the severity of pancreatitis, it is not specific to pancreatic pathology. Serum creatinine levels are related to kidney function and do not serve as a diagnostic tool for pancreatitis, making them irrelevant in this context. Thus, the elevation of serum lipase is both sensitive and specific enough to provide a confident diagnosis of acute pancreatitis.