Comparative Study between Serum Amylase and Lipase, BISAP Score, and CT Severity Index in Assessing the Severity of Acute Pancreatitis

Abstract

Background: Acute pancreatitis is a common gastrointestinal emergency with clinical presentations ranging from mild self-limiting inflammation to severe disease associated with organ failure and high mortality. Early prediction of disease severity is essential for timely management and improved outcomes. While serum amylase and lipase are routinely used as diagnostic biomarkers, their prognostic value remains limited. Clinical and radiological scoring systems such as the BISAP (Bedside Index for Severity in Acute Pancreatitis) and CTSI (CT Severity Index) may provide more reliable severity assessment. This study aimed to compare the effectiveness of serum amylase, serum lipase, BISAP score, and CTSI in predicting the severity of acute pancreatitis. Methods: This prospective hospital-based observational analytical study included 200 adult patients diagnosed with acute pancreatitis according to the Revised Atlanta Classification. Clinical, biochemical, and radiological parameters were recorded. Serum amylase and lipase levels were analyzed alongside BISAP score, CTSI, and MCTSI (Modified Computed Tomography Severity Index). Severity prediction was evaluated using correlation analysis, ROC (Receiver Operating Characteristic) curves, and multivariable logistic regression. Statistical analysis was performed using Jamovi software, with p <0.05 considered statistically significant. Results: The mean age of patients was 47.28 ± 13.11 years, with male predominance (66%). Alcohol was the most common etiology (51.5%). Severe acute pancreatitis was observed in 51.5% of patients. Serum amylase and lipase showed moderate correlation with severity scores (r ≈ 0.43–0.46). ROC analysis demonstrated fair predictive performance for serum amylase (AUC = 0.735) and serum lipase (AUC = 0.718). BISAP score showed excellent predictive accuracy (AUC = 0.974), while CTSI and MCTSI demonstrated near-perfect discrimination (AUC = 0.991 each). Strong positive correlations were observed among BISAP, CTSI, and MCTSI (r > 0.96). Multivariable analysis identified BISAP and MCTSI as strong independent predictors of severe acute pancreatitis. Conclusion: The BISAP score is an effective early bedside tool for severity prediction in acute pancreatitis, while CTSI and MCTSI provide the most accurate radiological assessment of disease severity. Serum amylase and lipase remain useful diagnostic biomarkers but have limited prognostic utility. Integration of BISAP and CT-based severity indices can improve early risk stratification and clinical management of acute pancreatitis.