Assessment of the severity of acute pancreatitis: no room for complacency

Assessing the severity of acute pancreatitis is an important initial step in the management of these patients. An ideal prognostic system or marker does not exist, and current approaches fall short of what is needed when dealing with individual patients. It is recommended that the evaluation of the performance of a particular prognostic system or marker should include the calculation of positive and negative likelihood ratios, derived from a combination of sensitivity and specificity. Knowing the pre-test probability of a particular endpoint and the likelihood ratios make it possible to derive the post-test probability for the presence or absence of that endpoint for the individual patient in that population. The change in probability from before to after the test gives an indication of the clinical usefulness of the test. Improving the performance of prognostic systems and markers remains a challenge and there is no room for complacency. There are two ways forward: either the prognostic systems and markers need to be used in a more intelligent way, with combinations, sequencing or artificial neural network techniques, or by the discovery of new markers that measure critical aspects of outcome determining pathophysiology. No lack of energy has been expended on the latter, while the former offers more immediate promise.