What is the initial workup for a patient presenting with right upper quadrant (RUQ) pain?

Initial Workup for Right Upper Quadrant (RUQ) Pain

Ultrasonography is the recommended first-line imaging study for patients presenting with right upper quadrant pain, accompanied by complete blood count (CBC), liver function tests (LFTs), and pancreatic enzymes. 1

Initial Evaluation

Laboratory Tests

• Required initial laboratory tests:
  • Complete blood count (CBC) - to evaluate for leukocytosis
  • Liver function tests (LFTs) - to assess liver abnormalities
  • Pancreatic enzymes - to evaluate for pancreatic pathology 1
• For women of reproductive age:
  • Beta human chorionic gonadotropin (β-hCG) testing before imaging 1

Imaging

• Ultrasonography is the initial imaging modality of choice because:
  • High sensitivity (81%) and specificity (83%) for acute cholecystitis
  • 96% accuracy for detecting gallstones
  • No radiation exposure
  • Cost-effectiveness 1
  • Can identify conditions beyond gallbladder disease 2

Diagnostic Algorithm

1. History and targeted physical exam

   • Document location, duration, and character of pain
   • Assess for Murphy's sign (pain with inspiration during RUQ palpation)
   • Evaluate for associated symptoms (fever, jaundice, nausea, vomiting)

2. Laboratory testing

   • Order CBC, LFTs, and pancreatic enzymes simultaneously
   • Add β-hCG for women of reproductive age

3. Initial imaging

   • Proceed with ultrasonography regardless of lab results
   • Evaluate for:
     • Gallstones and biliary tract abnormalities
     • Liver parenchymal disease
     • Pancreatic abnormalities
     • Other organ systems that may cause RUQ pain 1, 2

4. Additional imaging based on initial findings

   • If ultrasound is inconclusive:
     • For pregnant patients: MRI is preferred over CT 1
     • For non-pregnant patients with suspected biliary disease: Consider HIDA scan
     • For suspected non-biliary pathology: Consider contrast-enhanced CT 3

Important Considerations

Broadening the Differential Diagnosis

• If initial hepatobiliary workup is negative, consider:
  • Thoracic causes (pneumonia, empyema)
  • Musculoskeletal conditions
  • Referred pain from other sources 4, 2
  • Vascular, adrenal, renal, or gastrointestinal pathologies 2

Pitfalls to Avoid

• Do not rely solely on conventional radiography as it has limited diagnostic value in acute abdominal pain 1
• Do not use CT without IV contrast for suspected biliary disease as it has very limited value 1
• Do not stop at gallbladder evaluation if ultrasound is negative, as over one-third of patients initially thought to have acute cholecystitis actually have RUQ pain from other causes 2
• Remember that a normal CT does not rule out gallbladder disease, especially uncomplicated gallstones or early/mild cholecystitis 1

Special Populations

• Pregnant patients:
  • Ultrasound is first-line (sensitivity of 87% for gallstones)
  • MRI is preferred if ultrasound is inconclusive 1

When to Refer

• After initial imaging is completed with complex findings
• Evidence of biliary disease requiring ERCP
• Suspected primary biliary cholangitis (elevated GGT can be a marker) 1

By following this systematic approach to RUQ pain evaluation, clinicians can efficiently diagnose the cause and initiate appropriate management, improving patient outcomes and avoiding unnecessary testing.