Makindo Medical Notes

🩻 CT scan abdomen is the gold standard and more sensitive than plain films for suspected GI perforation. ⚠️ Findings may be masked in elderly or immunosuppressed patients.

📖 About

• Perforation of a gas- and bacteria-containing GI tract anywhere from oesophagus ➝ anus.
• 💨 Gas rises and can be seen trapped under the diaphragm on an erect CXR.
• Perforation leads to free intraperitoneal air and spillage of luminal contents → bacterial peritonitis + sepsis.

🧬 Aetiology

• Can occur at any point in the GI tract.
• Always consider in any patient presenting with an acute abdomen.
• Free air = red flag for overwhelming bacterial peritonitis and septic shock if untreated.

📸 Imaging: Free Air

⚠️ Causes

• Oesophagus: Caustic ingestion, endoscopic biopsy/dilatation, Boerhaave syndrome (post-vomiting), oesophageal tumour, chest trauma.
• Stomach: Peptic ulcer disease, NSAID-induced erosion, gastric cancer, penetrating trauma.
• Small bowel: Ischaemia, Crohn’s disease (fistula/erosion), trauma.
• Large bowel: Toxic megacolon (C. difficile, UC), diverticulitis, polypectomy/perforation during colonoscopy, trauma, cancer.

🩺 Clinical Features

Findings may be subtle in elderly or chronically immunosuppressed patients.

• 🚨 Sudden severe abdominal pain, worsened by movement.
• Rigidity, rebound, and percussion tenderness (“board-like abdomen”).
• Absent bowel sounds.
• Fever, tachycardia, hypotension (sepsis/shock).
• May coexist with bowel obstruction, diverticulitis, or malignancy.

🔍 Differentials

• Acute pancreatitis
• Myocardial infarction (can mimic upper abdo pain)
• Tubo-ovarian pathology (ruptured cyst, torsion)
• Ruptured abdominal aortic aneurysm (AAA)

🧪 Investigations

• 🩸 Bloods: FBC, U&E, LFTs, amylase, CRP – often raised WCC/CRP.
• 🩻 Plain films: CXR/AXR → free air under diaphragm, Rigler’s sign (air both sides of bowel wall), loss of psoas outline.
• 💧 Contrast swallow → useful if oesophageal perforation suspected.
• 🖥️ CT Abdomen = gold standard (sensitive for free air, perforation site, complications).

💉 Management

• 🚫 Nil by mouth (NPO).
• ABC resuscitation: IV fluids, oxygen, monitoring, analgesia.
• Broad-spectrum IV antibiotics (cover Gram-negatives + anaerobes).
• Immediate surgical review:
  • Perforation repair or resection (laparotomy/laparoscopy).
  • Selected cases (contained leak, stable patient) → conservative management with close observation.
• Consider ITU/HDU support if unstable.

📚 References

• NICE guidance on acute abdomen and GI emergencies.
• BNF – Antibiotic regimens for intra-abdominal sepsis.
• RCS guidelines on management of hollow viscus perforation.

📝 Revisions

• Updated September 2025