Extrapancreatic infections are common in acute pancreatitis and they are related to organ failure: a population-based study

Background Although the impact of pancreatic infections in acute pancreatitis has been studied extensively, there are no population-based data on extrapancreatic infections and their potential relation to organ failure. We aimed to study the occurrence of pancreatic and extrapancreatic bacterial infections in acute pancreatitis and their relation to patient outcome. Patients and methods All patients with first-time acute pancreatitis from 2003 to 2012 in a defined area in Sweden were retrospectively evaluated. Data on acute pancreatitis severity, organ failure, infections, and in-hospital mortality were collected. Results Overall, 304 bacterial infections occurred in 248/1457 patients (17%). Fifteen percent had extrapancreatic and 2% had pancreatic infections. The lungs (35%), the urinary tract (24%), and the bile ducts (18%) were the most common sites of extrapancreatic infections. Organ failure, severe acute pancreatitis, and in-hospital mortality were more common in patients with vs those without (pancreatic/extrapancreatic) infections (P < 0.05). Organ failure and severe acute pancreatitis occurred more frequently in pancreatic vs extrapancreatic infections (70% vs 34%,P < 0.001 and 67% vs 28%,P < 0.001), but in-hospital mortality did not differ between the two groups (7.4% vs 6.8%,P = 1.0). Both pancreatic and extrapancreatic infections were independent predictors of organ failure (P < 0.05). Out of culture-positive infections, 18% were due to antibiotic-resistant bacteria, without any significant difference between extrapancreatic vs pancreatic infections (P > 0.05). About two out of five infections were of nosocomial origin. Conclusion Extrapancreatic infections occurred in 15% and pancreatic infections in 2% of patients with first-time acute pancreatitis. Both pancreatic and extrapancreatic infections were independent predictors of organ failure, leading to increased mortality.