What is the appropriate workup for left upper quadrant (LUQ) pain?

Workup for Left Upper Quadrant Pain

CT scan of the abdomen and pelvis with IV contrast is the recommended first-line imaging study for patients presenting with left upper quadrant (LUQ) pain, as it provides the highest diagnostic accuracy for identifying common etiologies and potential complications. 1

Initial Assessment

• History elements to focus on:

  • Onset, duration, and character of pain
  • Radiation of pain
  • Associated symptoms (fever, nausea, vomiting)
  • Recent trauma or procedures
  • Prior abdominal surgeries
  • In women of reproductive age: menstrual history, pregnancy possibility

• Physical examination:

  • Vital signs with attention to fever and hemodynamic stability
  • Abdominal examination for tenderness, guarding, rebound
  • Presence of masses or organomegaly
  • Auscultation for bowel sounds

• Laboratory tests:

  • Complete blood count to assess for leukocytosis 1
  • Liver function tests if hepatobiliary disease is suspected 1
  • β-hCG testing in all women of reproductive age before imaging 1
  • Amylase/lipase if pancreatitis is suspected
  • Urinalysis to evaluate for renal/urologic causes

Imaging Approach

First-line Imaging:

• CT abdomen and pelvis with IV contrast - Highest diagnostic yield for most LUQ pathologies 1
  • Excellent detection of:
    • Splenic disorders (infarction, abscess, rupture)
    • Pancreatic inflammation
    • Vascular pathologies
    • Inflammation, abscess, perforation
  • Near 100% sensitivity for many common causes of LUQ pain

Alternative Imaging Options:

• MRI abdomen and pelvis - Consider when:

  • Patient has contraindication to CT contrast
  • Pregnancy with inconclusive ultrasound 1
  • Note: Less sensitive for extraluminal air and urinary tract calculi

• Ultrasound - Consider when:

  • Young patients (to minimize radiation exposure) 1
  • Suspected gynecologic etiology in premenopausal women (transvaginal) 1

Common Causes of LUQ Pain

1. Splenic disorders:

   • Splenic infarction, rupture, abscess, or enlargement
   • Best evaluated with CT with contrast

2. Pancreatic disorders:

   • Acute or chronic pancreatitis
   • Pancreatic pseudocyst or abscess
   • CT with contrast provides excellent visualization

3. Gastric pathology:

   • Gastritis, gastric ulcer, or gastric malignancy
   • May require endoscopic evaluation after initial imaging

4. Renal causes:

   • Nephrolithiasis, pyelonephritis
   • Non-contrast CT is preferred for urolithiasis (sensitivity 97-100%) 1

5. Vascular causes:

   • Abdominal aortic aneurysm
   • Mesenteric ischemia
   • CT angiography may be required

6. Rare causes:

   • Left-sided appendicitis (in patients with situs inversus or midgut malrotation) 2
   • Internal hernias 3

Diagnostic Pitfalls

• Relying solely on clinical assessment can result in misdiagnosis rates of 34-68% 1
• Plain radiography has limited sensitivity for most causes of LUQ pain and is not recommended as initial imaging 1
• In elderly patients, presentations may be atypical, and CT has been shown to change management in up to 51% of cases 1
• Post-operative patients require a lower threshold for advanced imaging to evaluate for complications 1

Special Considerations

• Pregnancy: Ultrasound should be first-line, followed by MRI if needed
• Elderly patients: May present with atypical symptoms; maintain low threshold for advanced imaging
• Post-operative patients: Consider anastomotic leaks, abscesses as potential causes 1
• Critically ill patients: May have gallbladder abnormalities even without acute cholecystitis 1

By following this algorithmic approach with appropriate imaging, the cause of LUQ pain can be accurately diagnosed in most cases, allowing for timely and appropriate management to improve patient outcomes.