Localized and systemic bacterial infections in necrotizing pancreatitis submitted to surgical necrosectomy or percutaneous drainage of necrotic secretions

Background: Infectious complications are observed in 40-70% of all patients with severe acute pancreatitis. Infections are associated with a significant increase in mortality rates. Methods: We evaluated the prevalence and characteristics of pancreatic and systemic infections in 46 patients with necrotizing pancreatitis submitted to surgical procedures during their hospital stay as well as the impact of such infectious complications on patient clinical outcome. Samples for microbiological cultures were taken at hospital admission from blood and bile and 2 days after invasive procedure from blood, drainage fluid, bile and necrotic tissues. Results: 74% patients with necrotizing pancreatitis had a localized or systemic infection. At admission, 15% of subjects had positive blood cultures whereas 13% had evidence of bacterial growth from bile cultures. Two days after the invasive procedures for removal of necrotic materials and fluids, blood cultures became positive in 30% of patients in spite of antibiotic prophylaxis and bile cultures resulted positive in 22% of cases. Furthermore, bacterial growth from drainage fluids was found in 30% and from homogenized necrotic material in 44% of cases. As refers to bacterial isolates, all patients had a monomicrobial infection. Carbapenems were the drugs with the best sensitivity profile. Mortality rate was significantly (p < 0.05) higher among patients with infection (17%) than subjects without infection (8%). Within the infected group, those subjects with evidence of systemic infection (positive blood cultures) developed more complications and demonstrated a higher (p < 0.05) mortality rate (28%) than those who had only a localized infection (10%). Conclusions: Infectious complications significantly increase mortality in patients with necrotizing pancreatitis. In addition, subjects with systemic infections developed more complications and demonstrated a higher mortality rate in comparison with those having a localized infection. In our study, the sensitivity pattern of the isolated microorganisms suggests to consider carbapenems as the best option for empirical treatment in patients with necrotizing pancreatitis who develop a clear-cut evidence of systemic or localized bacterial infection.