What is the initial workup for a patient presenting with right side pain?

Initial Workup for Right Side Pain

For patients presenting with right side pain, ultrasound is the recommended first-line imaging study for right upper quadrant pain, while CT with IV contrast is recommended for right lower quadrant pain. 1, 2

Approach Based on Pain Location

Right Upper Quadrant Pain

• First-line imaging: Abdominal ultrasound (rated 9/9 for appropriateness by ACR) 1

  • High sensitivity (88%) and specificity (80%) for acute cholecystitis 1
  • Advantages: No radiation exposure, can identify gallstones with 96% accuracy, evaluates bile ducts, and can identify alternative diagnoses 1
  • Key findings to assess: Gallstones, gallbladder wall thickening, sonographic Murphy sign, pericholecystic fluid 1

• Second-line options (if ultrasound is inconclusive):

  • Cholescintigraphy (rated 6/9): Higher sensitivity (97%) and specificity (90%) for acute cholecystitis 1
  • CT with contrast (rated 6/9): Useful for surgical planning or when ultrasound is inconclusive 1
  • MRI with and without contrast (rated 6/9): Similar sensitivity (85%) and specificity (81%) to ultrasound 1

Right Lower Quadrant Pain

• First-line imaging: CT abdomen and pelvis with IV contrast 1, 2

  • Excellent diagnostic accuracy for appendicitis (sensitivity 95%, specificity 94%) 1, 2
  • Can identify alternative diagnoses such as diverticulitis, bowel obstruction, and other causes 1

• Special populations:

  • Pregnant patients: Transvaginal and transabdominal ultrasound is first-line 2
  • When gynecologic etiology is suspected: Transvaginal and transabdominal ultrasound is first-line 2
  • When urolithiasis is suspected: Non-contrast CT (sensitivity 97-100%) 2

Laboratory Testing

• Obtain pregnancy status with β-hCG in all women of reproductive age 2
• Complete blood count to assess for leukocytosis 1
• Liver function tests if hepatobiliary disease is suspected 1

Key Clinical Considerations

Right Upper Quadrant

• Most common cause: Acute cholecystitis 1
• Classic presentation: Right upper quadrant pain, nausea, vomiting, fever 1
• Important caveat: Clinical presentation alone is insufficient for diagnosis; imaging is essential 1

Right Lower Quadrant

• Most common cause in adults: Appendicitis 1
• Alternative diagnoses to consider:
  • Right colonic diverticulitis (8% of RLQ pain cases) 2
  • Gynecological conditions (adnexal torsion, ruptured ectopic pregnancy) 2
  • Urolithiasis 2
  • Mesenteric adenitis, Meckel diverticulum, inflammatory bowel disease 3

Important Pitfalls to Avoid

1. Missing gynecological emergencies: Always obtain pregnancy status in women of reproductive age before imaging 2
2. Relying solely on clinical presentation: Studies show error rates of 34-68% for conditions like diverticulitis without imaging 2
3. Overlooking appendicitis in patients without classic symptoms: 15.6% of patients with appendicitis present with isolated right lower quadrant pain without fever or elevated inflammatory markers 4
4. Excessive radiation exposure: Consider ultrasound as initial imaging when appropriate, especially in young patients 2
5. Misdiagnosis in critically ill patients: Gallbladder abnormalities are common in critically ill patients even without acute cholecystitis 1

By following this evidence-based approach to right-sided pain, clinicians can efficiently diagnose and manage these common but potentially serious conditions while minimizing unnecessary radiation exposure and diagnostic delays.