S0131 Addition of Serum Bicarbonate and Anion Gap to Bedside Index of Severity in Acute Pancreatitis Score Do Not Improve Its Predictive Performance

Abstract

INTRODUCTION: Reliable and easy to use clinical prediction score is important in optimal management of acute pancreatitis. Currently, Bedside Index of Severity in Acute Pancreatitis (BISAP) score is the most accurate and easy to use clinical prediction score for acute pancreatitis (AP). Patients with AP are often hypovolemic at the time of presentation, which is a contributing factor to AP associated multi-organ dysfunction. We hypothesize that an elevated serum bicarbonate level and anion gap, which are readily available in most clinical settings, could improve performance of the BISAP score. Here, we assessed the performance of BISAP including serum bicarbonate in prognosticating moderate and severe acute pancreatitis. METHODS: Consecutive adults with acute pancreatitis admitted to our academic and two community hospitals between Jan 2014 and Dec 2019 were included in this study. We excluded patients with pregnancy or with diseases independently affecting their bicarbonate level (i.e., diabetic ketoacidosis, chronic renal failure stage 4 and 5). In cases of recurrent pancreatitis, only the initial episode was included. The severity of pancreatitis was defined based on the revised Atlanta classification: mild, moderate and severe. Performance of BISAP with and without bicarbonate levels and the anion gap was assessed using the ROC analysis. RESULTS: During the study period, 3 hospitals together had 653 admission for acute pancreatitis; a total of 444 unique patient admission were included. Of these, 316 patients had mild, 94 moderate and 34 patients had severe AP. Clinical characteristics of the cohort by severity of pancreatitis are summarized in Table 1. Bicarbonate levels were slightly lower in patients with moderate to severe acute pancreatitis, P = 0.038). The area under the curve (AUC) for BISAP score was 0.87 (95% CI 0.81–0.93) for severe and 0.72 (0.67–0.77) for moderate and severe pancreatitis combined. Inclusion of bicarbonate levels and the anion gap into BISAP improved AUC to 0.88 (0.81–0.95) and 0.89 (0.84–0.95), respectively (Table 2). This difference was not statistically significant. CONCLUSION: Inclusion of serum bicarbonate levels and the anion gap to the BISAP score did not improve its performance significantly.Table 1.: Clinical and laboratory characteristicsTable 2.: Discrimination by predictors—Two Revised Atlanta Classification