Peritonitis

Primary or spontaneous peritonitis is supposed to result from the colonization of pre-existing low-protein ascites in the absence of any obvious abdominal source. Escherichia coli and Klebsiella pneumoniae are the most common species responsible for the bacterial infection. The diagnosis is based on a positive ascitic fluid culture and a count of polymorphonuclear leucocytes above 250 cells/mm³. Radiological imaging exhibits commonly nonspecific findings such as ascitic fluid only.

Secondary peritonitis is caused by pre-existing diseases or lesions of the abdominal organs and from iatrogenic causes. Conditions that may lead to acute suppurative peritonitis, the most common form of acute peritonitis, include: perforated ulcer or tumour arising in the gastrointestinal tract, acute appendicitis, diverticulitis (see diverticulitis colon, penetrating trauma or iatrogenic perforation after percutaneous or endoscopic procedures.

Plain films of the abdomen in patients suspected of secondary peritonitis may demonstrate focal or generalized intestinal distension due to ileus. CT imaging may show nonspecific findings such as ascites or may be negative. Peritoneal inflammation can result also from physical or chemical injury to the peritoneal surface caused by spillage of a variety of irritant materials that are initially sterile such as bile or gastric acid. Iatrogenic causes include: intraperitoneal barium spillage, secondary to perforation of the bowel during radiographic study (Fig.1) or inadvertent introduction into the peritoneal cavity of materials used for surgical interventions. With time secondary bacterial contamination can occur with signs and symptoms similar to those of acute suppurative peritonitis. The presence of foreign materials (talc etc.) leads to the formation of granulomas and adhesions.

ALB