Acute Abdomen (Non-Traumatic, Overview)

• An acute abdomen can be defined as severe, persistent abdominal pain of sudden onset that requires immediate surgical or medical review
• An initial differential diagnosis is established after careful history, examination, considered blood tests and bed-side tests. Below is a list of differential diagnosis, which by no means is comprehensive
  • Gall bladder related disease
  • Acute pancreatitis
  • Bowel obstruction
  • Visceral perforation
  • Infection
  • Inflammatory
  • Gynaecological
  • Renal colic
  • Vascular
  • Referred pain - pneumonia, acute coronary syndrome, musculoskeletal, genitalia (torsion of testis), neurogenic
  • Metabolic
  • Autoimmune
  • Functional - irritable bowel syndrome
• Careful consideration should be given prior to requesting plain film radiography in the diagnostic alogorithm of an ‘acute abdomen’. They are infrequently diagnostic, often non-specific and are usually normal. A normal abdominal plain film series, DOES NOT exclude significant disease and hence should not be used (in the absence of certain clinical indications) to ensure ‘normality’ 1

Loin pain (renal colic)

Loin pain (acute pyelonephritis)

Pancreatitis (acute)

• Despite the known limitations of indiscriminate plain film abdominal radiography (PFR) in the evaluation of acute abdominal pain, it is still used with high frequency in patients presenting with acute abdominal pain 1, 2
• The ideal rate of PFR for acute abdominal pain should probably not exceed 10%, if indications for its use are stringently followed 1
• PFR has limited efficacy in an unselected population with acute abdominal pain, as it rarely alters clinical management 3,4
• Utilising PFR for the assessment of ‘non-specific abdominal pain’ is unlikely to yield a positive finding. Significantly, unrelated or incidental pathology can be identified and alter clinical management erroneously 5
• An erect abdominal radiograph, in most circumstances adds little additional diagnostic information 6,7
• The most likely clinical scenarios where PFR is likely to yield a finding that adds to or changes management includes; bowel obstruction, renal colic, bowel ischemia, and moderate-severe abdominal tenderness. 8 Note in the case of renal colic, a more sensitive test (LDCT renal colic protocol) is currently recommended
• There are number of reasons to ensure PFR of the abdomen is requested appropriately

• Indiscriminate use may identify incidental radiological abnormalities that are unrelated to the patients current presentation
• Financial cost
• Man power hours required in performing the test and its interpretation
• It is necessary for the referring practitioner to exclude pregnancy in female patients (appropriate age group), prior to radiation exposure
• Radiation exposure - it should be noted that the radiation from one PFR series of the abdomen is equivalent to 30 chest radiographs 2
• Therefore - recognised indications for PFR of the abdomen

• Suspected bowel obstruction or ileus
  • Supine abdominal radiograph (AXR)
  • Erect abdominal radiograph (AXR)
  • ± Erect chest radiograph (CXR) (lateral abdominal decubitus if patient unable to sit up)
• Suspected bowel perforation
  • Supine abdominal radiograph (AXR)
  • Erect abdominal radiograph (AXR)
  • ± Erect chest radiograph (CXR) (lateral abdominal decubitus if patient unable to sit up)
• Ingested foreign body
  • Supine abdominal radiograph (AXR)
• Severe abdominal pain / tenderness of unknown origin requiring opiate analgesia
  • Supine abdominal radiograph (AXR)
  • Erect abdominal radiograph (AXR)
  • ± Erect chest radiograph (CXR) (lateral abdominal decubitus if patient unable to sit up)

Cholecystitis (suspected acute)

Iliac fossa pain (acute right)

bowel obstruction (suspected)

Iliac fossa pain (acute left)