A higher serum lipase cut-off improves the diagnosis of acute pancreatitis in patients with non-epigastric abdominal pain

Summary: Acute pancreatitis (AP) may present with non-epigastric, i.e., atypical pain. Current guidelines recommend the same diagnostic lipase cut-off irrespective of pain location, which increases cross-sectional imaging requirements. 863 emergency department patients with serum lipases >3-times upper-limit of normal (ULN) were accrued over 6 years. Alternate lipase cut-offs for atypical pain were studied in training (n = 539) and validation cohorts (n = 324) using imaging-proven AP as the reference. At >3-times ULN lipase cut-off, 15% (i.e., 129/863) patients had atypical pain. These were imaged more often (89% vs. 75%) but had lower AP diagnoses (34% vs. 62%) than others. A >7.5-times ULN cut-off for atypical pain reduced imaging by 40%, increased imaging-proven AP diagnosis (56–77% in both cohorts), increased specificity by 2-fold, while retaining sensitivity of ≥95%. Therefore, a >7.5-fold ULN improves AP diagnosis in atypical, i.e., non-epigastric pain. This may reduce costs, expedite AP management when cross-sectional imaging is not feasible, and improve outcomes.