Secondary pancreatic infections: are they distinct clinical entities?

BACKGROUND: Infected pseudocysts, pancreatic abscesses, and infected pancreatic necroses have been proposed as distinct clinical entities in terms of treatment and outcome. To evaluate this classification, we reviewed the clinical course and bacteriologic findings of pancreatic infections.
METHODS: Of 1299 patients with pancreatitis or a related complication admitted over a 7-year period, 64 (4.9%) with culture-documented secondary pancreatic infections were reviewed with regard to cause, clinical course, bacteriologic findings, and outcomes.
RESULTS: Group I consisted of 23 patients with infected pseudocysts; group II, 20 patients with pancreatic abscesses; and group III, 21 patients with infected pancreatic necrosis. The causes were alcohol in 36%, biliary tract disease in 30%, and postoperative in 16%, with no significant difference between groups. Patients in group I had abdominal pain or a mass without accompanying signs of sepsis, whereas patients in groups II and III had sepsis. In group I, 15 patients were treated with internal drainage, four with percutaneous drainage, and four with external drainage. In group II, three had percutaneous drainage, 15 operative drainage, and two open packing. In group III, 19 patients had operative drainage and two had open packing. Morbidity occurred in 26% of patients in group I, 40% in group II, and 90% in group III (p less than 0.001). Mortality rates were 9% in group I, 25% in group II, and 48% in group III (p less than 0.01). Enteric organisms were present in 66% of isolates, with no difference between groups, suggesting a common mode of infection.
CONCLUSIONS: Despite similar bacteriologic findings, infected pseudocysts, pancreatic abscesses, and infected pancreatic necroses have significantly different presentations, clinical courses, and outcomes, confirming that they are distinct entities. This distinction is important when therapeutic outcomes are compared.