Bowel perforation (summary)

Bowel perforation is an acute surgical emergency where there is a release of gastric or intestinal contents into the peritoneal space.

Reference article

This is a summary article for bowel perforation. There is no dedicated reference article.

Summary

• presentation
  • history
    • may depend on the location of the perforation
      • severe and generalised abdominal pain (upper)
      • gradual and localised pain (lower)
    • anorexia, nausea and vomiting
  • examination
    • rigid abdomen and generalised tenderness
    • guarding and rebound
    • bowel sounds range from quiet to absent
• pathology
  • gastric and duodenal ulceration
  • infection (diverticulitis, appendicitis), ischaemia and cancer
  • blunt and penetrating trauma
  • ingestion of corrosive materials
  • iatrogenic causes (ERCP, colonoscopy, laparotomy, biopsy)
• radiology
  • an erect plain radiograph is sensitive for small volumes of free gas
  • a supine abdominal radiograph may show signs of free gas
  • CT with IV contrast is the gold standard investigation
    • free gas and fluid within the peritoneal cavity
• treatment
  • fluid resuscitation and IV antibiotics
  • surgical intervention is often required to close the perforation
    • bowel resection may be required
  • mortality increases the longer surgical treatment is delayed

Radiographic features

Role of imaging

• confirm free intraperitoneal gas
• determine the underlying cause
• if possible, identify the site of perforation

Plain radiograph

An

Erect CXR

• erect chest radiograph is often obtained if there is clinical suspicion of bowel perforation. Chest radiographs are CXR
• very sensitive to even small amounts of gas within the peritoneal cavity.
• seen as a crescent under the diaphragm

Abdominal radiographs are often also performedX-ray

• performed for other reasons, e.g. Several to identify bowel obstruction
• several signs of pneumoperitoneum may be seen on a supine abdominal radiograph including , e.g. Rigler sign. However, they rarely add information because pneumoperitoneum on an erect CXR will prompt surgery or a CT.

CT

Abdominal

• abdominal CT with IV contrast can be used to confirm hollow viscus perforation.
• CT is very sensitive for even the smallest amounttiny volumes of free gas within the abdomen. It is seen
• triangles or bubbles or gas out with the bowel
• anti dependant - rising to the top of the supine abdomen as triangles or bubbles or gas outwitha cavity, e.g. behind the bowel.

  CT is also useful to detect

  abdominal wall
• associated fluid within the peritoneal cavity which may also leak from an intestinal perforation. Peritoneal fluid does not always mean perforation.is helpful but non-specific

Finding the cause

CT is also useful to determine the cause of the perforation and is therefore very helpful before surgical intervention.

Where there is more gas than fluid, think upper GI perforation (e.g. duodenal ulcer). Where there is more fluid than gas, lower GI perforation is more likely.