The ascites to serum amylase ratio identifies two distinct populations in acute pancreatitis with ascites

While the characteristics of ascites in the setting of chronic pancreatitis are well established, little has been written about the characteristics of spontaneous, clinically apparent ascites in the setting of acute pancreatitis. Our aim was to define the characteristics of clinically apparent ascites complicating acute pancreatitis, particularly with regard to outcomes.We performed a search of our hospital's discharge records for ICD codes 577.0 (acute pancreatitis) and 789.5 (ascites). Clinical and laboratory variables in survivors and nonsurvivors were compared using a Mann-Whitney U test.We identified 59 records of which 25 cases had ascites fluid analysis. Only the ascites amylase (p = 0.033) and the ascites to serum amylase ratio (p = 0.002) correlated with mortality. Setting a cutoff of 1, the ascites to serum amylase ratio achieved a sensitivity of 83% and a specificity of 92% as a predictor of mortality.The ascites to serum amylase ratio identifies 2 sets of patients with ascites complicating acute pancreatitis. In patients with a high ratio, ascites may result from a localized duct disruption. In patients with a low ratio ascites may be secondary to comorbid conditions or a capillary leak. In acute pancreatitis with clinically apparent ascites, the ascites to serum amylase ratio may be a predictor of mortality.