S0104 Diagnostic Trends and Clinical Course of Non-Gallstone Non-Alcohol-Associated Acute Pancreatitis Within a Large Health System

INTRODUCTION: Acute pancreatitis (AP) is a leading gastrointestinal cause of hospitalization in the United States. Up to two-thirds of cases are related to alcohol use (AAP) or gallstones (GAP). There is limited data on the prevalence, patient characteristics and severity of non-biliary-non-alcohol-associated AP (NNAP). We analyzed and contrasted real-world diagnostic trends and clinical outcomes of NNAP with AAP and GAP within a large multi-state health system. METHODS: ICD-10 codes for AP were used to identify adult patients presenting to emergency departments (ED) within the MedStar Health system between March 2015 and June 2019. These included ED visits and inpatient admissions. Manual review yielded 2542 charts with complete clinical information, 1212 of which have AP as defined by Revised Atlanta Classification (RAC) and documented etiologies as either GAP, AAP or NNAP. Charts with unknown etiology or idiopathic were excluded. GAP, AAP and NNAP groups were then compared for the following characteristics and outcomes: patient age, lipase, presenting symptoms, imaging received, workup of etiology, treatment variables, complication rate, readmission rate and length of stay. Statistical analysis was performed using GraphPad PRISM. RESULTS: A total of 1903 patients met RAC for AP and 690 patients were excluded due to having unknown or idiopathic etiology in documentation. The prevalence of NNAP was 10.7% and these patients were more likely to have elevated lipase (OR 1.65, P < 0.02) and AP defined by RAC (OR 2.01, P < 0.0001) compared to patients with GAP and AAP. Incidence of workup was higher in the NNAP group (OR 4.81, P < 0.0001). Drug-induced (DI, 37.6%), hypertriglyceridemia (TG, 21.7%) and anatomic abnormality (14.3%) were the 3 most common etiologies in patients with NNAP (Figure 1). Compared to GAP and AAP, the NNAP group was more likely to require ICU level of care (OR 1.88, P = 0.02), experience complications (OR 1.57, P = 0.02) and be readmitted within 30 days (OR 2.02, P = 0.0025). Length of stay was significantly longer for patients with NNAP compared to GAP and AAP (6.1 vs. 4.6 vs. 3.8 days, P = 0.0001; Figure 2). CONCLUSION: Patients with NNAP experienced higher morbidity, readmission rate and longer hospital stay. DI, TG and anatomic abnormality were the most common causes. This is an unique subset of patients who require closer monitoring and appropriate targeted therapies.Figure 1.: Etiologies of patients with acute pancreatitis other than gallstone or alcohol.Figure 2.: The average length of stay of patients with NNAP was significantly longer than that of patients with GAP and AAP (P < NNAP = non-gallstone-non-alcohol-associated acute pancreatitis GAP = gallstone-associated acute pancreatitis AAP = alcohol-associate acute pancreatitis.