Retrospective study of patients with acute pancreatitis: is serum amylase still required?

OBJECTIVES

To assess the role of serum amylase and lipase in the diagnosis of acute pancreatitis. Secondary aims were to perform a cost analysis of these enzyme assays in patients admitted to the surgical admissions unit.

DESIGN

Cohort study.

SETTING

Secondary care.

PARTICIPANTS

Patients admitted with pancreatitis to the acute surgical admissions unit from January to December 2010 were included in the study.

METHODS

Data collated included demographics, laboratory results and aetiology. The cost of measuring a single enzyme assay was £0.69 and both assays were £0.99.

RESULTS

Of the 151 patients included, 117 patients had acute pancreatitis with gallstones (n=51) as the most common cause. The majority of patients with acute pancreatitis had raised levels of both amylase and lipase. Raised lipase levels only were observed in additional 12% and 23% of patients with gallstone-induced and alcohol-induced pancreatitis, respectively. Overall, raised lipase levels were seen in between 95% and 100% of patients depending on aetiology. Sensitivity and specificity of lipase in the diagnosis of acute pancreatitis was 96.6% and 99.4%, respectively. In contrast, the sensitivity and specificity of amylase in diagnosing acute pancreatitis were 78.6% and 99.1%, respectively. Single lipase assay in all patients presenting with abdominal pain to the surgical admission unit would result in a potential saving of £893.70/year.

CONCLUSIONS

Determining serum lipase level alone is sufficient to diagnose acute pancreatitis and substantial savings can be made if measured alone.