Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content +++ INTRODUCTION ++ Intra-abdominal infections are those contained within the peritoneum or retroperitoneal space. Two general types of intra-abdominal infections are discussed throughout this chapter: peritonitis and abscess. Peritonitis is defined as the acute, inflammatory response of peritoneal lining to microorganisms, chemicals, irradiation, or foreign body injury. It may be classified as either primary or secondary. With primary peritonitis, an intra-abdominal focus of disease may not be evident. In secondary peritonitis, a focal disease process is evident within the abdomen. An abscess is a purulent collection of fluid separated from surrounding tissue by a wall consisting of inflammatory cells and adjacent organs. It usually contains necrotic debris, bacteria, and inflammatory cells. +++ PATHOPHYSIOLOGY ++ Table 42–1 summarizes many of the potential causes of bacterial peritonitis. Appendicitis is the most frequent cause of abscess. Intra-abdominal infection results from entry of bacteria into the peritoneal or retroperitoneal spaces or from bacterial collections within intra-abdominal organs. When peritonitis results from peritoneal dialysis, skin surface flora are introduced via the peritoneal catheter. In primary peritonitis, bacteria may enter the abdomen via the bloodstream or the lymphatic system, by transmigration through the bowel wall, through an indwelling peritoneal dialysis catheter, or via the fallopian tubes in female patients. In secondary peritonitis, bacteria most often enter the peritoneum or retroperitoneum as a result of disruption of the integrity of the gastrointestinal (GI) tract caused by diseases or traumatic injuries. When bacteria become dispersed throughout the peritoneum, the inflammatory process involves the majority of the peritoneal lining. Fluid and protein shift into the abdomen (called “third spacing”) may decrease circulating blood volume and cause shock. Peritonitis often results in death because of the effects on major organ systems. Fluid shifts and endotoxins may cause hypotension and shock. An abscess begins by the combined action of inflammatory cells (eg, neutrophils), bacteria, fibrin, and other inflammatory components. Within the abscess, oxygen tension is low, and anaerobic bacteria thrive. ++Table Graphic Jump LocationTABLE 42–1Causes of Bacterial PeritonitisView Table||Download (.pdf) TABLE 42–1 Causes of Bacterial Peritonitis Primary (spontaneous) bacterial peritonitis Peritoneal dialysis Cirrhosis with ascites Nephrotic syndrome Secondary bacterial peritonitis Miscellaneous causes Diverticulitis Appendicitis Inflammatory bowel diseases Salpingitis Biliary tract infections Necrotizing pancreatitis Neoplasms Intestinal obstruction Perforation Mechanical GI problems Any cause of small bowel obstruction (adhesions, hernia) Vascular causes Mesenteric arterial or venous occlusion (atrial fibrillation) Mesenteric ischemia without occlusion Trauma Blunt abdominal trauma with rupture of intestine Penetrating abdominal trauma Iatrogenic intestinal perforation (endoscopy) Intraoperative events Solid organ transplant in the abdomen Peritoneal contamination during abdominal operation Leakage from GI anastomosis (GI, gastrointestinal.) +++ MICROBIOLOGY ++ Primary bacterial peritonitis is often caused by a single organism. In children, the pathogen is usually group A Streptococcus, Escherichia coli, Streptococcus pneumoniae, or Bacteroides species. When peritonitis occurs in association with cirrhotic ascites, E. coli is isolated most frequently. Peritonitis in patients undergoing peritoneal ... Your MyAccess profile is currently affiliated with '[InstitutionA]' and is in the process of switching affiliations to '[InstitutionB]'. Please click ‘Continue’ to continue the affiliation switch, otherwise click ‘Cancel’ to cancel signing in. Get Free Access Through Your Institution Learn how to see if your library subscribes to McGraw Hill Medical products. Subscribe: Institutional or Individual Sign In Username Error: Please enter User Name Password Error: Please enter Password Forgot Username? Forgot Password? Sign in via OpenAthens Sign in via Shibboleth