Infectious complications in patients with severe acute pancreatitis.

This study aims to investigate the clinical characteristics of infectious complications in severe acute pancreatitis (SAP). From September 2003 to March 2005, 140 patients with SAP were retrospectively identified. SAP was defined by the diagnostic criteria formulated for SAP at the 2002 Bangkok World Congress of Gastroenterology in Thailand. Clinical data of the infected and non-infected patients was compared and the characteristics of infection were also analyzed. There were 44 patients who developed infectious complications with a rate of 31.4% (44/140). The severity index, the incidence of complications and mortality, was significantly higher in the infected patients than in the non-infected patients (P<0.05). Of 65 episodes of infection, infected (peri) pancreatic necrosis accounted for 47.7% (31/65), pneumonia for 27.7% (18/65), bacteremia for 10.8% (7/65), urinary tract infection for 6.1% (4/65), and gastrointestinal tract infection for 7.7% (5/65). The earliest infection was observed in pneumonia (10.7±2.5 days), followed by bacteremia (13.7±1.5 days), gastrointestinal tract infection (16.8±3.9 days), infected (peri)pancreatic necrosis (17.6±2.9 days), and urinary tract infection (20.5±4.8 days). Gram-negative bacteria were preponderantly found, comprising 56.6% (64/113) of the isolated strains. Gram-positive bacteria and fungus accounted for 22.1% (25/113) and 21.2% (24/113) of the isolated strains, respectively. Infectious complications in patients with SAP occurred in those who had severe episodes, and consequently complicated the clinical courses. Infected (peri)pancreatic necrosis is the most susceptible and pneumonia is the earliest. Gram-negative bacteria were predominant in multi-microorganisms.