Complications of peritonitis

Local (peritoneal) complications

Peritoneal inflammation can be localized or generalized, which directly determines the severity of the patient's condition.

• Local circumscribed peritonitis. In this case, the inflammatory focus is isolated from the free abdominal cavity by adhesions, scars, or an inflammatory infiltrate. Such delimitation often leads to the formation of local intra-abdominal abscesses.
• Generalized (diffuse) purulent peritonitis. It develops upon perforation of a hollow organ (e.g., a gangrenously altered appendix) and the body's inability to delimit the process. Fibrinous-purulent or putrid exudate accumulates in the abdominal cavity. A morphological feature of diffuse inflammation is the presence of densely adhered intestinal loops.

With the progressive spread of infection across the peritoneum (transition to unrestricted forms), the stage and phase of peritonitis inevitably deepen, which sharply worsens the prognosis.

Abscess formation and adhesive disease

The purulent-destructive process in the abdominal cavity is often accompanied by the formation of localized accumulations of pus. Peritonitis can be complicated by the formation of the following abscesses:

1. Interintestinal — located between adhered loops of the small or large intestine.
2. Subphrenic — localized in the upper floor of the abdominal cavity under the dome of the diaphragm (classified as rare, but extremely severe complications).
3. Pelvic — accumulate in the pelvic cavity.
4. Lumbar and periappendicular abscesses.

In addition, a pronounced adhesive process and the presence of inflammatory infiltrates in the abdominal cavity are the main causes of the development of acute intestinal obstruction.

Inflammatory infiltrates

One of the options for local containment of infection is the formation of an infiltrate.

• Essence of the process: The body tries to isolate the destructively altered organ from the free abdominal cavity. The greater omentum and adjacent organs actively participate in this process, tightly "enveloping" the focus of inflammation.
• Clinical course: The infiltrate develops immediately after an acute attack. Unlike specific infectious lesions (e.g., actinomycotic infiltrate), a nonspecific inflammatory conglomerate is capable of rapid regression against the background of adequate conservative anti-inflammatory therapy.
• Outcomes: If treatment proves ineffective, suppuration of the infiltrate occurs with the formation of a local abscess, which requires surgical intervention.

Systemic and vascular complications

Generalization of infection in peritonitis poses the greatest threat to the patient's life. Severe systemic consequences include:

• Abdominal sepsis (septicemia). It develops when the infection breaks through into the systemic bloodstream. To prevent this life-threatening condition, a thorough revision of the abdominal cavity during surgery (even with a visually intact organ wall) and timely antibiotic therapy in the postoperative period are required.
• Septic shock — a critical drop in blood pressure against the background of a systemic inflammatory response.
• DIC syndrome (disseminated intravascular coagulation) — a severe disorder of the hemostatic system with the formation of microthrombi and subsequent depletion of coagulation factors.
• Pylephlebitis. A specific vascular complication representing purulent inflammation of the portal vein. It arises as a consequence of infectious thrombophlebitis of the small veins draining the primary focus of inflammation. A natural outcome of pylephlebitis is the formation of a pylephlebitic liver abscess.

Rare complications and prognostic signs

In clinical practice, less typical consequences of past peritonitis and destructive processes in the abdominal cavity also occur:

• Development of anaerobic gangrene of the anterior abdominal wall (e.g., after appendectomy).
• Formation of external (cutaneous) and internal (vesical) fistulae.
• Retroperitoneal phlegmon (more often occurs with an atypical, retrocecal location of the infection source).

It is important to remember that a prolonged disease anamnesis (about a day from the onset of pain) combined with hectic fever (body temperature rising to 39 °C) is an extremely unfavorable prognostic sign. Such a clinical picture indicates a high risk of progression of phlegmonous inflammation into a gangrenous form with perforation and rapid development of generalized peritonitis.

Class and exam questions

What else to study on this topic

• Clinical and anatomical forms and stages of development of acute appendicitis
• Morphological changes in the intestinal wall during destructive inflammation
• Appendiceal infiltrate: differential diagnosis and management tactics
• Principles of antibiotic therapy and prevention of abdominal sepsis
• The concept of appendicopathy and "false" appendicitis

Other topics in the "Additional Topics" section

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.