S3086 Predicting Gallstone Pancreatitis: A Pilot Study

Abstract

INTRODUCTION: Acute pancreatitis, a life-threatening disease with increasing incidence worldwide, is the most common gastrointestinal cause of hospitalization in the United States. Gallstone Pancreatitis (GP) makes up for about 40%-70% of cases. Distinguishing GP from other causes is of clinical importance as it can change the management, primarily whether the patient should undergo cholecystectomy. METHODS: This retrospective, cross-sectional chart review examined patients ≥18 years old with a diagnosis of pancreatitis at a single hospital in South Texas between September 2014 and December 2019. Cases were included if two of three criteria were met: 1) acute abdominal pain; 2) serum lipase ≥3 times the upper limit of normal (920 units/L); and/or 3) findings of acute pancreatitis on CT scan. Patients with post-ERCP pancreatitis were excluded from analyses. Differences in descriptive statistics between GP and non-GP were evaluated using t-test and chi-square. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for the diagnosis of GP were calculated separately for ALT, AST, lipase, alkaline phosphatase (AP) and total bilirubin (T Bili). Statistical analyses were conducted using R version 4.0.0. RESULTS: After chart-review, 405 patients met the inclusion criteria for this study. We found that 37.8% had a diagnosis of GP. The mean age of included patients was 53.1 years (SD = 18.8). No significant difference in Body Mass Index was found between GP and non-GP (GP: 31.5 vs non-GP: 30.7, P = 0.325). The Female:Male ratio was significantly higher in GP than non-GP (GP: 1.83 vs non-GP: 1.1, P = 0.020). AST, ALT, lipase, AP, and T Bili were also significantly higher in GP than non-GP (Table 1). The PPV for ALT >150 units/L to diagnose GP was 88% (range: 81-93). AST, lipase, AP, and T Bili findings are shown in Table 2 and Figure 1. CONCLUSION: The majority of cases were attributed to GP. Moreover, in 35.5% of the cases, the underlying etiology was not identified. In patients with acute pancreatitis we determined that ALT >150 units/L has a PPV of 88% of diagnosing GP. Lipase, AP, AST and T Bili did not show the same potential as a single laboratory value; however, they were all significantly higher in GP compared to non-GP. Further research combining laboratory values and risk factors would help pave the way to the creation of a predictive scoring system for GP, thus decreasing unnecessary studies and diagnoses of ‘idiopathic’ acute pancreatitis.Table 1.: Descriptive StatisticsTable 2.: Sensitivity, Specificity, PPV and NPV for Diagnosing Gallstone PancreatitisFigure 1.: Laboratory Values ROC Curves.