Clinical utility and economic burden of routine serum lipase determination in the Emergency Department

Background: Serum lipase is a rapid and reliable laboratory test central to diagnosing acute pancreatitis (AP). Routine use in the emergency department (ED) setting for all cases of abdominal pain or as part of a standard laboratory biochemical profile may lead to unnecessary expenses. Aim: To examine the utility of serum lipase determination at a tertiary care centre ED. Methods: Retrospective cross-sectional study of ED patients having serum lipase determination over a 12-month period. Electronic medical records were reviewed for indication and interpretation leading to additional diagnostic imaging, specialist consultation, interventions or hospital admission. Results: A total of 24 133 adult patients visited the ED during the study period: 4976 (20.6%) had serum lipase determination, 614 (12.4%) had abnormal lipase, 130 of which (21.1%) were above the diagnostic threshold for acutre pancreatitis (AP) (>3× ULN). A total of 75 patients had confirmed AP (0.3% of all adult ED visits). The positive and negative predictive values of serum lipase (>3× ULN) for AP were 43.6% and 99.6%, respectively. One thousand eight hundred and ninety patients (38.0%) had no abdominal pain on history or physical examination. In this group, the total charge associated with lipase determination was $51 030 with 251 (13.3%) elevated lipase values triggering cross-sectional abdominal imaging in 61 (24.3%) patients and unwarranted gastroenterology consultation in three (1.2%) for an additional charge of $28 975. Conclusions: Serum lipase is widely overutilised in the emergency setting resulting in unnecessary expenses and investigations. Evidence-based review of clinical guidelines and more restrictive testing can result in substantial cost savings and improved patient care.