Clinical scenario

A 44 year old man presents to the emergency department with a four hour history of severe epigastric pain. You consider a diagnosis of pancreatitis and organise a serum amylase to be taken. You wonder whether a single normal serum amylase result is sufficiently sensitive to rule out pancreatitis in this patient.

Three part question

In [patients with abdominal pain] does [a normal serum amylase] exclude [the diagnosis of pancreatitis]?

Search strategy

Medline 1966-07/03 and Embase 1980-07/03 using the OVID interface. [({exp Abdominal pain/ OR abdominal pain.mp} OR {exp Pancreatitis/ OR pancreatitis, acute necrotising/ OR pancreatitis, alcoholic/ OR pancreatitis.mp}) AND {exp Amylases OR amylase$ OR amylase.mp}] AND [exp Sensitivity and Specificity OR (sensitivity.mp AND specificity.mp)] LIMIT to human AND English.

Search outcome

Altogether 191 papers found of which four papers were relevant to the original question (table 4).

Comment(s)

The gold standard for the diagnosis of pancreatitis is considered to be surgical examination at laparotomy or pancreatic histology. Often in practice such information is either unavailable or obtained at postmortem examination. In the absence of a readily available gold standard it becomes necessary to evaluate serum diagnostic markers against radiological methods such as CT. Only two studies used an independent “gold standard” for all patients to compare the diagnostic test under consideration. Despite this weakness all the above studies except one reported sensitivities below 95%, especially in alcohol related pancreatitis cases.

CLINICAL BOTTOM LINE

In patients presenting to the emergency department with acute abdominal pain a normal serum amylase concentration is not sufficiently sensitive to rule out the diagnosis of acute pancreatitis.