What is the most appropriate initial step for a vitally stable patient with mild right upper quadrant abdominal pain 1 week after a road traffic accident?

Initial Management: Perform Abdominal Ultrasound

For a vitally stable patient presenting with mild right upper quadrant pain one week after a road traffic accident, the most appropriate initial step is to perform an abdominal ultrasound to evaluate for delayed traumatic complications, particularly hepatobiliary injury. 1, 2, 3

Rationale for Ultrasound as First-Line Imaging

• The American College of Radiology recommends ultrasound as the first-line diagnostic test for right upper quadrant pain evaluation, rating it 9/9 (usually appropriate). 1, 2

• Ultrasound is ideal in this clinical scenario because it can detect:

  • Delayed hepatic injuries (subcapsular hematomas, lacerations) 1
  • Biliary complications from trauma (hemobilia, bile duct injury, biloma) 4
  • Gallbladder pathology that may have been precipitated by trauma 1, 2
  • Free fluid in the abdomen suggesting ongoing hemorrhage 3

• The one-week delay between trauma and presentation is critical—delayed presentations of blunt abdominal trauma can manifest as previously undiagnosed injuries, including diaphragmatic herniae with visceral strangulation, hepatic injuries, or biliary complications. 5

Why Emergency Department Referral Is Not Necessary

• This patient is vitally stable with mild pain, which does not meet criteria for immediate emergency department referral. 2

• Emergency referral is indicated when patients present with:

  • Hemodynamic instability 3
  • Fever with leukocytosis suggesting acute cholecystitis or cholangitis 2
  • Peritoneal signs suggesting perforation or acute surgical abdomen 3
  • Severe pain or clinical deterioration 6

• Since this patient lacks these concerning features, outpatient ultrasound evaluation is appropriate and avoids unnecessary emergency department utilization. 2, 3

Why Blood Work Alone Is Insufficient

• While laboratory testing (complete blood count, liver function tests, lipase) provides valuable information, it cannot definitively rule out significant intra-abdominal pathology that requires imaging for diagnosis. 3

• Many traumatic abdominal injuries, including hepatic lacerations, subcapsular hematomas, biliary injuries, and delayed diaphragmatic herniae, require imaging for detection and cannot be excluded by laboratory values alone. 5, 3

• Blood work should be obtained concurrently with ultrasound, not as a substitute for imaging. 3

Clinical Algorithm for This Patient

1. Order right upper quadrant ultrasound immediately to evaluate for:

   • Hepatic injury (hematoma, laceration, subcapsular collection) 1
   • Biliary pathology (stones, wall thickening, pericholecystic fluid, bile duct dilatation) 1, 2
   • Free fluid suggesting hemorrhage 3
   • Diaphragmatic abnormalities if visualized 5

2. Obtain concurrent laboratory studies including:

   • Complete blood count to assess for anemia or leukocytosis 3
   • Liver function tests (AST, ALT, alkaline phosphatase, bilirubin) to evaluate hepatobiliary injury 3
   • Lipase if pancreatic injury is considered 3

3. If ultrasound is negative or equivocal and clinical suspicion remains high for traumatic injury:

   • Proceed to CT abdomen/pelvis with IV contrast for comprehensive evaluation of solid organ injuries, bowel injuries, and vascular complications 7, 3
   • CT has significantly advanced since older studies and provides superior sensitivity for detecting traumatic abdominal pathology 7

4. If ultrasound demonstrates biliary pathology requiring further characterization:

   • MRCP provides 85-100% sensitivity and 90% specificity for biliary tree evaluation and is superior to CT for suspected biliary sources of RUQ pain 1, 4

Critical Pitfalls to Avoid

• Do not dismiss mild symptoms in the setting of recent trauma—delayed presentations of blunt abdominal trauma can be life-threatening, including strangulated diaphragmatic herniae and evolving hepatic injuries. 5

• Do not skip imaging and rely solely on clinical examination or laboratory values, as many traumatic injuries require imaging for diagnosis. 3

• Do not order CT as the initial test when ultrasound is appropriate—ultrasound provides rapid, cost-effective diagnosis without radiation exposure and is the recommended first-line modality for RUQ pain. 1, 2, 3

• Recognize that the one-week interval between trauma and presentation places this patient in the window for delayed traumatic complications, which mandates imaging evaluation even with mild symptoms. 5