Right-Sided Abdominal Pain with Nausea and Vomiting: Workup and Management
For a patient presenting with 2 days of right-sided abdominal pain with nausea and vomiting, obtain CT abdomen and pelvis with IV contrast as the initial imaging study, as this has the highest diagnostic yield (sensitivity 85.7-100%, specificity 94.8-100%) and reduces negative appendectomy rates to 1.7-7.7%. 1
Initial Clinical Assessment
Focus your history and physical examination on these specific elements:
- Pain characteristics: Ask if pain started periumbilically and migrated to the right lower quadrant (classic for appendicitis, though only present in ~50% of cases) 1
- Associated symptoms: Fever, anorexia, and leukocytosis complete the classic triad, but their absence doesn't exclude appendicitis 1
- Right upper quadrant pain: Consider biliary pathology (cholecystitis, cholelithiasis)
- Reproductive history: In patients with female reproductive organs, determine last menstrual period and pregnancy status immediately 2
Laboratory Workup
Order these tests concurrently with imaging:
- Complete blood count (leukocytosis supports but doesn't confirm appendicitis)
- C-reactive protein
- Hepatobiliary markers (if right upper quadrant component)
- Urinalysis (to exclude urolithiasis/UTI)
- Pregnancy test (mandatory in all patients of reproductive age) 2
- Lipase (if epigastric component present)
Imaging Strategy
Primary Recommendation: CT Abdomen/Pelvis with IV Contrast
CT has become the most useful diagnostic modality because preoperative CT reduces negative appendectomy rates from 16.7% (clinical evaluation alone) to 8.7%. 1 The evidence strongly supports this approach:
- Use IV contrast: Sensitivities range 90-100%, specificities 94.8-100% 1
- Enteral contrast is NOT necessary when IV contrast is used 1
- Non-enhanced CT has lower sensitivity (90% vs 90-100% with IV contrast) 1
Alternative Imaging Considerations
Ultrasound has significant limitations in adults:
- Appendix not visualized in 27.7-45% of cases 1
- When appendix is visualized: sensitivity 81.7%, specificity only 53.9% 1
- Reserve ultrasound for pregnant patients or when CT is contraindicated 3, 2
For pregnant patients specifically:
Symptomatic Management
While arranging imaging and awaiting results:
Antiemetic therapy: Administer 5-HT3 receptor antagonists (ondansetron) as first-line, as they act on both central and peripheral receptors 4
IV fluid resuscitation: Replace volume losses from vomiting to prevent hypovolemia and electrolyte imbalances 4
Nasogastric decompression: Consider if repeated vomiting to prevent aspiration 4
Common Pitfalls to Avoid
- Don't delay imaging for oral contrast administration: This increases time to diagnosis without improving accuracy when IV contrast is used 1
- Don't rely on "classic" presentation: Only 50% of appendicitis patients present with the textbook periumbilical-to-RLQ migration pattern 1
- Don't skip pregnancy testing: Ectopic pregnancy, ovarian torsion, and PID must be excluded in reproductive-age patients 2
- Don't use ultrasound as primary imaging in adults: The 27.7-45% non-visualization rate makes it unreliable for excluding appendicitis 1
Alternative Diagnoses to Consider
Based on right-sided location:
- Right upper quadrant: Cholecystitis, cholelithiasis, hepatitis
- Right lower quadrant: Appendicitis (most common surgical cause), ovarian pathology, ectopic pregnancy, urolithiasis, Crohn's disease, diverticulitis (if cecal)
- Flank component: Pyelonephritis, urolithiasis 2
Disposition
If CT confirms appendicitis: Immediate surgical consultation for appendectomy
If CT is negative but clinical suspicion remains high: Consider alternative diagnoses based on imaging findings and repeat examination in 12-24 hours if symptoms persist
The evidence unequivocally supports CT with IV contrast as the gold standard, having increased from 7.2% utilization in 1997 to 83.3% in 2016 precisely because of its superior diagnostic performance 1.